Add uid to Instructions so it can be animated

uid adding is handled in a new ObjectWithUid C class,
which both EventDispatcher and Instruction inherit from.
This allows running animations on graphics instructions.

Test for a instruction animation is insluded.
Merge pull request #1337 from encukou/uid-for-instructions

Add uid to Instructions so it can be animated
Merge pull request #1339 from peristeri/master

Fix broken test
tutorial: add final example of notes. now we have to have for the steps
Expand devel installation docs for Mac OS X.
Fixes bug where double/triple taps always True on Windows

touch.is_double_tap and touch.is_triple_tap are always True
on Windows even if the second/third tap is outside the
double/triple tap time. Fixes #1298.
Merge branch 'master' of https://github.com/kivy/kivy into windows_tap
doc: revisions to core/audio/__init__.py
Merge pull request #1349 from Zen-CODE/api7

doc: revisions to core/audio/__init__.py
Merge pull request #1348 from dkmadigan/windows_tap

Windows Double/Triple Tap Fixes #1298
Implement py2k iteration interface

zero chance of problem in other code.  makes py2.7 work for running examples/widgets/screenmanager
doc: revisiosn to core/camera
Merge pull request #1350 from Zen-CODE/api8

doc: revisions to core/camera
doc: revisions to core/clipboard
doc: revisions to core/clipboard
Merge pull request #1351 from Zen-CODE/api9

doc: revisions to core/clipboard
kivy-mode.el:
Added kivy-indent-shift-left and kivy-indent-shift-right.
docs: revisions to core/image part 1
Merge pull request #1354 from Zen-CODE/api10

docs: revisions to core/image part 1
Merge pull request #1352 from RenWenshan/Wenshan

kivy-mode.el: