Log message

Adds ability for IM messages to send HTML, fixes  issue 32 

Committing most of Jonas's patch from http://rietku.appspot.com/3001
It seems to be missing a file, common/templatetags/test/format.py so
I have subbed in a blank file for now.

	Modify	/trunk/common/api.py	diff
	Modify	/trunk/common/protocol/xmpp.py	diff
	Add	/trunk/common/templates/im	diff
	Add	/trunk/common/templates/im/im_comment.html	diff
	Add	/trunk/common/templates/im/im_comment.txt	diff
	Add	/trunk/common/templates/im/im_entry.html	diff
	Add	/trunk/common/templates/im/im_entry.txt	diff
	Modify	/trunk/common/templatetags/format.py	diff
	Add	/trunk/common/templatetags/test/format.py	diff
	Modify	/trunk/common/test/util.py	diff
	Modify	/trunk/common/tests.py	diff
	Modify	/trunk/components/dummy_xmpp_service/__init__.py	diff
	Modify	/trunk/settings.py	diff