fix ofGet/SetBackgroundColor, replaces #1401

ofSetBackgroundColor has never worked properly, this fixes it
ofGetBackground is deprecated for ofGetBackgroundColor
ofBgColor removed completely, this will break old code but was really wrong
ofbBgClear removed for ofGetBackgroundAuto

also renderers now have to implement:

	startRender
	endRender

and windows need to call it in display.

windows don't need to set anymore the vieport, clear the bg...
now the renderers do that instead, before the window had to ask
the renderer if it had to clear the background and with which
color which was mixing the responsabilities of both classes and where
that info was stored
Merge branch 'master' into bugfix-ofGet/SetBackgroundColor
getTextureReference -> getTexture
*getTexture -> *getTexturePtr
android_configure apothecary: add more include paths
Merge branch 'master' of github.com:openframeworks/openFrameworks
ofPixels::getPixels -> getData. getPixels deprecated
Merge branch 'master' into refactor-getTextureReference

Conflicts:
	examples/3d/3DPrimitivesExample/src/ofApp.cpp
	examples/ios/PrimitivesExample/src/ofApp.mm
Merge pull request #3319 from arturoc/refactor-getTextureReference

getTextureReference -> getTexture
Merge branch 'master' into bugfix-ofGet/SetBackgroundColor

Conflicts:
	libs/openFrameworks/gl/ofShader.cpp
Merge pull request #3315 from arturoc/bugfix-ofGet/SetBackgroundColor

fix ofGet/SetBackgroundColor, replaces #1401
ofTexture: deprecate bAllocated
CHANGELOG
ofBuffer::getBinaryBuffer -> getData
ofPixels: remove deprecated calls
ofVideoPlayer: remove deprecated calls
ofCairoRenderer: fix clear bg + set default size from viewport. Closes #524
ofGLRenderer: remove deprecated calls
ofAppRunner: remove unneded call to set bg
ofGraphics immediate mode style primitivves -> ofDraw*

ofRect -> ofDrawRectangle
ofTriangle -> ofDrawTriangle
ofCircle -> ofDrawCircle
...