* camel/camel-types.h: New header with the typedefs for all camel
	classes. Now the class headers can just include this and the
	header for the parent type. This makes it possible for
	CamelService to include a CamelSession without creating an
	#include loop.

	* camel/*:
	* composer/e-msg-composer-attachment-bar.h:
	* mail/folder-browser.c:
	* mail/message-list.c: frob #includes to match the new reality

svn path=/trunk/; revision=1850