With recent changes in the performance schema default sizing parameters,
the memory used by a mysqld binary increased accordingly.

This negatively affects the MTR test suite,
because running several tests in parallel now consumes more ressources.

The fix is to leave the default production values unchanged,
and to configure the MTR environment to limit memory
used when running tests in the test suite, which is ok
because only a few objects are typically used within a test script.

This fix:
- changed the default configuration in MTR to use less memory
- adjusted the performance schema tests accordingly

Note that 1,000 mutex instances was too short and caused test failures
in the past in team trees, so the default used is now 10,000 in MTR.

The amount of memory used by the performance schema itself
can be observed with the statement SHOW ENGINE PERFORMANCE_SCHEMA STATUS

 create data dir correctly in initial_database target on Windows
 handle case where INSTALL_MYSQLTESTDIR is empty (e.g someone does not want
 to install tests)

Merge cleanup, fixed a build warning:

my_getopt.c:156: warning: 'opt_found' may be used uninitialized in this function

       made libmysqld/Makefile.am to have same licence as libmysqld/CMakeLists.txt

per-file comments:
  libmysqld/Makefile.am
Bug#54906      Inconsistent license of libmysqld
        Added GPL license header instead of Library GPL.

Problem:
- ORDER BY for utf8mb4_bin, utf16_bin and utf32_bin returned
  results in a wrong order, because old functions
  (supporting only BMP range) were used to handle these collations.
- Additionally, utf16_bin did not sort supplementary characters
  between U+D700 and U+E000, as WL#1213 specification specified.

            "Access compatibility" syntax

The "wild" "DELETE FROM table_name.* ... USING ..." syntax
for multi-table DELETE statements is documented but it was
lost in the fix for the bug 30234.

The table_ident_opt_wild parser rule has been added
to restore the lost syntax.

 - Remove include of ha_ndbcluster_tables.h from mysqldump.c

so test case has to be updated.

      
The lock_type is upgrade to TL_WRITE from TL_WRITE_DELAYED for
INSERT DELAYED when inserting multi values in one statement.
It's safe. But it causes an unsafe warning in SBR.
      
Make INSERT DELAYED safe by logging it as INSERT without DELAYED.

            == MYSQL_TYPE_LONGLONG

A MIN/MAX() function with a subquery as its argument could lead
to a debug assertion on debug builds or wrong data on release
ones.

The problem was a combination of the following factors:

- Item_sum_hybrid::fix_fields() might use the argument
(args[0]) to calculate 'hybrid_field_type' which was later used
to decide how the data should be sent to the client.

- Item_sum::make_field() might use the argument again to
calculate the field's type when sending result set metadata to
the client.

- The argument could be changed in between these two calls via
  Item::set_arg() leading to inconsistent metadata being
  reported.

Here is what was happening for the bug's test case:

1. Item_sum_hybrid::fix_fields() calculates hybrid_field_type
as MYSQL_TYPE_LONGLONG based on args[0] which is an
Item::SUBSELECT_ITEM at that time.

2. A temporary table is created to execute the
query. create_tmp_field_from_item() creates a Field_long object
according to the subselect's max_length.

3. The subselect item in Item_sum_hybrid is replaced by the
Item_field object referencing the newly created Field_long.

4. Item_sum::make_field() rightfully returns the
MYSQL_TYPE_LONG type when calculating the result set metadata.

5. When sending the actual data, Item::send() relies on the
virtual field_type() function which in our case returns
previously calculated hybrid_field_type == MYSQL_TYPE_LONGLONG.

It looks like the only solution is to never refer to the
argument's metadata after the result metadata has been
calculated in fix_fields(), since the argument itself may be
different by then. In this sense, Item_sum::make_field() should
never be used, because it may rely on the argument's metadata
and is only called after fix_fields(). The "default"
implementation in Item::make_field() should be used instead as
it relies only on field_type(), but not on the argument's type.

Fixed by removing Item_sum::make_field() so that the superclass
implementation Item::make_field() is always used.

Free memory allocated by the server for all plugins,
with or without deinit() method.

            not tested by ABI check

plugin_audit.h and plugin_ftparser.h are now subject
for ABI check. plugin.h is now tested implicitly.

Also fixed broken ABI check cmake rules.

Handle combined instrument states of ENABLED and/or TIMED:

ENABLED TIMED
1 1 Aggregate stats, increment counter
1 0 Increment counter
0 1 Do nothing
0 0 Do nothing 

Problem: trailing spaces were stripped using 8-bit code,
so the truncation result length was incorrect, which led
to an assertion failure.
Fix: using multi-byte safe code.

After fix for bug 39653 the shortest available secondary index was used for
full table scan. Primary clustered key was used only if no secondary index
can be used. However, when chosen secondary index includes all fields of the
table being scanned it's better to use primary index since the amount of
data to scan is the same but the primary index is clustered.
Now the find_shortest_key function takes this into account.

Before this fix, the server did not recognize 'short' (as in -a)
options but only 'long' (as in --ansi) options
in the startup command line, due to earlier changes in 5.5
introduced for the performance schema.

The root cause is that handle_options() did not honor the
my_getopt_skip_unknown flag when parsing 'short' options.

The fix changes handle_options(), so that my_getopt_skip_unknown is
honored in all cases.

Note that there are limitations to this,
see the added doxygen documentation in handle_options().

The current usage of handle_options() by the server to
parse early performance schema options fits within the limitations.
This has been enforced by an assert for PARSE_EARLY options, for safety.