Added test for sched_yield() possibly in -lposix4 on Solaris

  Restored accidently removed line to check for zlib

  Removed unused files
.del-my_winsem.c:
  Delete: mysys/my_winsem.c
.del-my_semaphore.c:
  Delete: mysys/my_semaphore.c
.del-my_semaphore.h:
  Delete: include/my_semaphore.h

Fix to check library in use during runtime.
Fix for Bug#16995, "idle connections not being killed due to timeout when NPTL is used".

  Don't build server when configured --without-server (bug#23973)

  Fix undefined behaviour.
Many files:
  Reenabled build outside ource tree

  Raise version number to 4.1.23

(4.1 version, with post-review fixes)
  
  The fix for another Bug (6439) limited FROM_UNIXTIME() to
  TIMESTAMP_MAX_VALUE which is 2145916799 or 2037-12-01 23:59:59 GMT,
  however unix timestamp in general is not considered to be limited 
  by this value. All dates up to power(2,31)-1 are valid.
  
  This patch extends allowed TIMESTAMP range so, that max
  TIMESTAMP value is power(2,31)-1. It also corrects
  FROM_UNIXTIME() and UNIX_TIMESTAMP() functions, so that
  max allowed UNIX_TIMESTAMP() is power(2,31)-1. FROM_UNIXTIME()
  is fixed accordingly to allow conversion of dates up to
  2038-01-19 03:14:07 UTC. The patch also fixes CONVERT_TZ()
  function to allow extended range of dates.
  
  The main problem solved in the patch is possible overflows
  of variables, used in broken-time representation to time_t
  conversion (required for UNIX_TIMESTAMP).

BUG#23427 incompatible ABI change in 5.0.26?
   - Use the icheck tool if avaliable and compare the current mysql.h to a version
controlled reference file 

  Corrected typo

  Man page for mysqld command move to section 8 (bug#21220)

have a better test (and so this should be null-merged there).

ALSO!  Make it so that it accepts NPTL as a valid _equivalent_ implementation.

  Update NDB version as well

  Stepped up to 4.1.22

  Updated release number 4.1.16a

  Stepped up to 4.0.28

  Changed version to 4.1.20

code. (Bug #13621)

  Check for crypt() in libc first (bug#16478)

  Cloned off 4.1.18, new release number 4.1.19

  Generated "libmysql.ver" will be in \$(top_builddir)

libmysqlclient versioning when linked with GNU ld.

  Corrected "include/readline" link for "make distcheck"

own CFLAGS (ditto for CXXFLAGS). (Bug #12640)

   directory - these files are now maintained in the mysqldoc
   repository and included in the source distribution during the
   release build. Updated the configure.in script and Makefiles to
   create the man page file list at build time
 - Updated the file list in the RPM spec file to include all currently
   available man pages (this can not be done with wildcards, as
   the man pages are spread across several subpackages. However, RPM
   warns about unpackaged files, so newly added man pages can be 
   spotted)

signal handlers are set up, the blocking flags for sockets are set,
and which thread-related functions are used. (Bug #8731)

  Enable "make distcheck" to work

  Flag -DHAVE_DARWIN_THREADS not needed for darwin9