Fixed hiding ACTIVE widgets getting them stuck in ACTIVE state, blocking all future events from reaching other widgets.
Changed CMakeLists.txt to accept SFML 2.x instead of only 2.0.
Reimplemented sfg::Canvas, rewrote sfg::Renderer::Display() interface to allow sf::Windows to be used as targets for GUI rendering as well, changed OpenGL example to use an sf::Window to better demonstrate OpenGL functionality, fixed some annoying CMake quirks.
Moved spinner RenderQueue update logic into Engine-side code to decouple the Widget from it's Engine implementation and make it easier for custom Engines to be written for it.
Made sure to restore coherency between wiped states cache and OpenGL texture binding by unbinding any bound textures after wiping the cache. (Reported by FRex: http://en.sfml-dev.org/forums/index.php?topic=6112.msg70971#msg70971)
Added missing Canvas.cpp example to repository.
Updated SFML extlib to version 2.1.
Updated changelog, updated version number in Doxygen config.
Added FONT.LICENSE and CHANGELOG to install target.