enfore minimum down state time
fix line circle angles
fix state event handling
Merge pull request #2531 from kived/buttonbehavior-minimum-state-time

enfore minimum down state time
Merge pull request #2554 from kived/line-circle-angles

fix line circle angles
core:img_io add py3 support, img_sdl2 add save support
Merge pull request #2556 from kivy/py2_py3

core:img_io add py3 support, img_sdl2 add save support
uix:ToggleButton Behavior make it consistent with ButtonBehavior
Merge pull request #2557 from kivy/_do_release

uix:ToggleButton Behavior make it consistent with ButtonBehavior
dioc: fixes example formatting in uix/listview.py
doc: added note on intializing selection for the ListAdapter
doc: corrected explanation for multiple selection
rpi: add stencil support when creating the egl context. Closes #1302
remove CET note
doc: pep8 in example in uix/listview.py

pep8 spacing and alignment in example for CompositeListItem in
uix/listview.py
Merge branch 'master' of https://github.com/kivy/kivy
Enable cyclic garbage collection to EventObservers.
Merge pull request #2566 from matham/event-gc

Enable cyclic garbage collection to EventObservers.