* add axis convenient methods and matrix display example
* wrestled wayward space back into docstring
* color map names are case sensitive on Linux
* docstring fix for PlotItem
* protect AxisItem.linkToView from being obscured by DateAxisItem override
* replaced setOrigin method by promoted setPos and setScale
* made tri-state axes switching explicit
* reverted setRect behavior, documentation pass for ImageItem
* minor text adjustment
* implmented some suggested revisions
* fix input parsing for setRect and add tests so that I don't break it again
* don't try to re-add transform after clearing it
* changed example and doc image generators to pg.exec()
* removed commented-out code
* cleaned up transform eqaulity assertion
* restored devoured comment
* restored devoured comment
