minor doc
Support QtDBus in Qt M4 macro
Some reshuffling to pull lots of noise out of Rainback.cpp
Pulled out more stuff from Rainback

This necessitated creating a convenience library for our proxies (to
prevent name collisions). It also required much churning in Rainback.cpp
and main.cpp to get everything working.
Moved GL.cpp into proxy/GL.cpp (and converted to a plugin-style syntax)
Moved QPoint and QSize out of Rainback.cpp
Added simple DBus support
Build config.h in include, where it belongs
Remove an errant debug statement
DBus code now uses the plugin idiom

This code is also guarded by a #ifdef, which ensures it will not break
systems that don't have DBus, like Windows.
Initial QWebView support
Make DBus support fail a bit more cleanly