Fixes the following:
* Read past buffer end in intToDatetime / intToTime
* Allow intToTime to convert datetime
* Allow intToTime to convert shortened time values
* Allow stringToTime to convert datetime and int time values
* Fix saturation / bad values in intToTime and stringToTime
* Fix TIME return in STR_TO_DATE()
* Fix NULL return on type inequality for TIMEDIFF()
* Fix zero day calculation error in ADDTIME()/SUBTIME()
* Fix DATETIME to int calculation error in aggregate bit operations
* Make the new harderning flags optional with -DSECURITY_HARDENED_NEW
This fixes hex() so that it outputs the hex of the ASCII for the time
data to make it aligned with MariaDB. It also fixes the following
functions so that they use NOW() as a DATETIME with the input TIME added
to it:
* weekday()
* yearweek()
* monthname()
* last_day()
* year()
* weekofyear()
* week()
* to_days()
* quarter()
* month()
* dayofyear()
* dayofweek()
* dayofmonth()
* day()
* date()
