fixed QString -> str conversions in flowchart
Added export methods to GLViewWidget
Enabled piecewise export
delete texture and framebuffer after export
export uses padding to prevent edge effects
bugfix in ViewBox.clear
ImageItem informs ViewBox when its size changes
Minor edits
New methods in use for converting array -> QImage.
This fixes memory leaks with PyQt 4.10 _except_ when using makeQImage(copy=False).
Tested on 4.9.3 and 4.10.2; need to be tested against other versions.
corrected exception error message
strip all withspace
Merge branch 'inp_strip'

Conflicts:
	pyqtgraph/Point.py
	pyqtgraph/frozenSupport.py
	pyqtgraph/functions.py
	pyqtgraph/graphicsItems/ImageItem.py
	pyqtgraph/graphicsItems/LegendItem.py
	pyqtgraph/graphicsItems/PlotCurveItem.py
	pyqtgraph/graphicsItems/ViewBox/ViewBox.py
	pyqtgraph/multiprocess/remoteproxy.py
	pyqtgraph/opengl/GLViewWidget.py
	pyqtgraph/opengl/items/GLLinePlotItem.py
	pyqtgraph/opengl/shaders.py
	pyqtgraph/widgets/ValueLabel.py