Problem was that it tried to run partitioning function calls when
opening a partitioned table, when it was explicitly disabled.
Solution is to check if the partitioning plugin is ready to use before
using any partitioning specific calls.
- As a sideeffect of the patch to generate lex_hash.h only once
on the machine where the source dist was produced, a problem
was found when compiling a mysqld without partition support - it
would crash when looking up the lex symbols due to mismatch between
lex.h and the generated lex_hash.h
- Remove the ifdef for partition in lex.h
- Fix minor problem with"EXPLAIN PARTITION" when not compiled with
partition(existed also without the above patch)
- Add test case that will be run when we don't have partition
support compiled into mysqld
- Return error ER_FEATURE_DISABLED if user tries to use PARTITION
when there is no support for it.
