[patch] plugin build process improvements

[Antony Dovgal]

Hello all.

At the moment MySQL plugin process is overly complicated - in order to build a plugin one
must perform the following actions:
1) fetch MySQL sources
2) run `./configure`
3) run `make`, as my_config.h is created by make, not ./configure.

Patch #1 (mysql_my_config.h.diff) addresses this problem by eliminating step #3.

Patch #2 (mysql_defines.h) fixes another problem: if MySQL server has been built with
--with-debug option, 
it uses SAFE_MUTEX (and SAFEMALLOC for "full" debug), but these defines are nowhere to be
found, 
hence one needs to add them manually in order to build a working plugin (there are no
compile errors, 
just random runtime problems because of different structure size).
The patch adds these defines to config.h (and my_config.h).

Please review attached patches.
You can also find them here: 
http://dev.daylessday.org/diff/mysql_my_config.h.diff
http://dev.daylessday.org/diff/mysql_defines.diff

Thanks in advance.

-- 
Wbr, 
Antony Dovgal

Attachment: [text/x-patch] mysql_defines.diff

Attachment: [text/x-patch] mysql_my_config.h.diff