tests: added some tests for some of the app dialogs

still haven't found a way to close modal dialogs, so those aren't being
tested yet
FF: gamma correction needs to come /after/ the context and opengl
FF: a new file added to help get around the broken loading of avbin
DOCS: changelog
DOCS: added demo of interleaved staircase

also had to change the gitignore file to do this
DOCS: bumped version number
DOCS: updated index and changelog
Merge branch 'master' of github.com:peircej/psychopy
BF: fixed bug when using ElementArrayStim with numpy 1.7.1

caused by the new need to force things into contiguous order when doing
reshapes/concatenates. Symptom was that most of the elements came up
with sf=0 (ie very noticeable error)
FF: new bug with scaling of images when size=None

The code to track requestedSize was set /after/ size had been given a value
so always had a value even when the user didn't request one.
DOC: Fixed several typos and small inconsistencies in documentation.
Merge pull request #381 from philippwiesemann/master

DOC: Fixed several typos and small inconsistencies in documentation.