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 git://github.com/psychopy/psychopy
BF: fixed broken manual ('semi') calibration

Existing manual gamma calibration tools weren't working (older wx.XXX
code it appeared) so I re-wrote the luminance level dialog input code.