Code review comment for lp:~vkolesnikov/pbxt/pbxt-drizzle-merge

some comments on changes:

1. I had to extend the scope of _try (b) {} _catch (b) {} section to include the second assignment of "thd" variable as otherwise gcc gives a warning stating that the variable can be clobbered by the longjmp.

2. added check for existence of pbxt.location.[frm|dfe] to xt_create_table_frm()

3. other changes are either Drizzle-specific fixes and don't affect MySQL code or are renames of variables, hiding of unused parameters, etc...