now renders in a separate thread and Window can set active thread
removed calls to Window::setActive
Merge pull request #26 from swloper/master

Build script updates
Merge branch 'master' of github.com:vheuken/Purity2D
Got rid of static renderer

Textures now get created the first time they are drawn, instead of
on initial load.
added comments to clarify previous changes
RenderSystem destructor now doesn't join thread
cleaned up a tad
got rid of the thread stuff for now
window now knows if focus is lost
greys out window when input loses focus
Merge pull request #27 from swloper/master

Mostly iOS work
Merge pull request #3 from vheuken/master

Merging back