NO_ZERO_DATE, NO_ZERO_IN_DATE SQL MODES and make their
         functionality part of STRICT MODE

This is the 5.7 version of the patch.
      
This patch removes the functionality of ERROR_FOR_DIVISION_BY_ZERO,
NO_ZERO_DATE, NO_ZERO_IN_DATE SQL MODES and makes their 
functionality part of STRICT MODE.

All the tests are updated according to the new behaviour.

NOTE:Here STRICT MODE refers to STRICT_ALL_TABLES and
STRICT_TRANS_TABLES.

NOTE:Also a small refactoring is done for TIME_NO_ZERO_* flags
which makes the code conceptually clear and easy to understand.
Previously in old code there was an implicit dependency between
MODE_NO_ZERO* and TIME_NO_ZERO* flags and they could be freely 
mixed and the code was confusing and conceptually
wrong.
With the elimination of MODE_NO_ZERO_* flags handled in this WL,
TIME_NO_ZERO_* flags which control the datetime behaviour
are also updated.
This refactoring is also done to keep the existing behaviour if 
SQL_MODE is traditional/STRICT.