Squashed 'gui/pyqtgraph/' changes from 26730ad..8268ccf

8268ccf Added GLImageItem.setData()
ee40f57 Merge branch 'develop' of github.com:pyqtgraph/pyqtgraph into develop
ed0b956 Correct LegendItem addItem to use next available row
17dbdfb Merge pull request #77 from tfeldmann/patch-1
6e4b2f4 Fixed typo in readme

git-subtree-dir: gui/pyqtgraph
git-subtree-split: 8268ccfa655feef7e2f6b5128b012f53201474d1
Merge commit '2b5abe7d36c93564af2a72bd41f9749e1b22c779' into develop