uix:TabbedPanel switch to previous tab if touched tab is removed before we
can switch to it.
Fix relative import in audio_sdl.pyx. Sound now works on iOS!
(tito actualy fixed this, I just did the testing)
graphics/opengl: implemented/fixed a few Python bindings.
audio_sdl: Use Mix_Playing() instead of Mix_GetChunk() to detect if the sound has finished in ._check_play()
Spelling correction
Merge pull request #1205 from Zen-CODE/Doc_English_Improvements_44

doc: revisions to docs/contribute-unittest.rst
uix: `disabled` property for base widgets
uix: first pass at making some compound widgets honor `disabled`
property.
uix:Widgets make sure all compound widgets work with disabled
increase size of atlas to 1024 for accomodating all images in one atlas
uix: Widget move disabling of child widgets to `on_disabled` instead of
binding. and move back to a 512 image for atlas.
uix: Widget.disabled final pass making sure every widget honors disabled
property and doc fixes.
examples:KivyCatalog delay auto-reloading while cursor movement
Merge branch 'master' of https://github.com/kivy/kivy
Add Button.trigger_action() which is a simple way to simulate a button press
without actual touch events.
Make the documentation a little clear, explictly mentioning that both on_press and on_release actions will be triggered
uix:widgets.disabled fix kv for slider
examples:KivyCatalog fix popup and boolean  sections
Update examples.rst

Fix typos
uix:Splitter revert back to `horizontal` orientation if `size_from`
property is changed from `top`/`bottom` to `right`/`left`