Fixed compiler warnings (a lot of hidden variables detected by the Forte compiler)
Added a lot of 'version_xxx' strings to 'show variables'
Prevent copying of TMP_TABLE_PARAM (This caused core dump bug on Solaris)
Fixed problem with printing sub selects to debug log
client capabilities included into libmysqld
some API methods became "virtual"
lots of duplicated code removed
IMHO all the above made library's code way more pleasant to look at, didn't it?