Add checking of more warnings + fix some of them
Add a .gitignore file
follow lensref changes
Merge branch 'misc-changes' of https://github.com/mgsloan/lgtk into mgsloan-misc-changes

Conflicts:
	lgtkdemo/LGtk/Demos/IntListEditor.hs
	lgtkdemo/LGtk/Demos/Main.hs
	src/LGtk.hs
	src/LGtk/Backend/GLFW.hs
	src/LGtk/Effects.hs
Merge branch 'mgsloan-misc-changes'