2.3 Fixes Date Issues

The DATE_CMD variable was found to be very limited, so I replaced it with a new variable called DATE_FORMAT. This requires a change in blog.conf, so replace DATE_CMD=`date '+%B %d, %Y %r'` with DATE_FORMAT="%B %d, %Y %r" (or similar line). This will hopefully resolve the difficulties that came up when trying to change an entry's date format.