and some SP-related cleanups.
- We don't have separate stage for calculation of list of tables
to be prelocked and doing implicit LOCK/UNLOCK any more.
Instead we calculate this list at open_tables() and do implicit
LOCK in lock_tables() (and UNLOCK in close_thread_tables()).
Also now we support cases when same table (with same alias) is
used several times in the same query in SP.
- Cleaned up execution of SP. Moved all common code which handles
LEX and does preparations before statement execution or complex
expression evaluation to auxilary sp_lex_keeper class. Now
all statements in SP (and corresponding instructions) that
evaluate expression which can contain subquery have their
own LEX.
Lots of small fixes to multi-precision-math path
Give Note for '123.4e'
Added helper functions type 'val_string_from_real()
Don't give warnings for end space for string2decimal()
Changed storage of values for SP so that we can detect length of argument without strlen()
Changed interface for str2dec() so that we must supple the pointer to the last character in the buffer
Under strict mode MySQL will generate an error message if there was any conversion when assigning data to a field.
Added checking of date/datetime fields.
If strict mode, give error if we have not given value to field without a default value (for INSERT)
