WL#3481: Partitioning: Add support for temporal data types

MySQL will implement support for partitioning
using temporal data types (DATE, TIME, TIMESTAMP
and DATETIME), as well as support for partitioning
using all functions that return a temporally-related
value (e.g. QUARTER(), MONTH(), WEEK(), YEARWEEK()).

Support for partitioning using temporal data types is
implemented by support for general data types as is
performed by WL#3352. 

So I suggest using this worklog for extending the support
for partition functions with temporal content. These
functions need to be strictly non-decreasing. Thus
YEARWEEK will be ok, QUARTER, MONTH and WEEK will not,
thus we should new functions YEARQUARTER and YEARMONTH
and make those able to perform range based partition pruning.

See also BUG#13436 Partitions: most data types don't work.