update values for environment variables KIVY_xxx.
Complete pyinstaller hooks.
Document id.__self__.
Remove dynamic class to not confuse beginner.
Document difference between graphics list properties and kivy list properties.
Document properties of properties.
document valid kv expressions and statements.
Mention ask_update needs to be called after blit.
add docs about coordinate systems and relative type layouts.
Clearify label text/texture size.
Merge pull request #1820 from matham/camera

Various doc improvements