Can't see how mysqld_safe can work with current setup, so make it look
in $pkglibdir/mysql too.

Other cleanups.

Remove libmysqld-debug.a, it doesn't exist in current packages?

flags are being used correctly.

Don't create empty ChangeLog.

locations.

Add ChangeLog.

Make mysql.info optional.

prefers to take docs directly from the source tree.

correct location.

which was detected during the build of 5.5.3-m3.
This requires version 9 of IBM C++ to help.

More fixes will still be needed, it is very strict
(or rather: a bit picky?) about templates.

about handling the debug plugin files,
also "ha_example.*" are dropped.

While here:

 - split INSTALL_*DIR variables into two sections, first set the major
   variables, then second set the minor ones, using the major where
   appropriate.

 - format the settings for easier parsing (at least with a wide terminal)