richedit: Cannot undo setting of default character format.

richedit: Cannot undo setting of default character format.

This also reverts commit 2b52dd845097f16076c0185b02a003f63898dcab:
wordpad: Empty the richedit undo buffer on creation.

The reverted commit I created to fix an issue that only applied to Wine,
but it just masked the issue which was in richedit controls.  The
default character format was set in two places while wordpad was
starting up, and caused wordpad to have two undo items at startup.