BF: In QuestHandler.addResponse(), do not try to replace existing intensity if intensities list is empty.
Merge remote-tracking branch 'upstream/master'
Merge pull request #438 from hoechenberger/master

BF: Do not try to replace existing intensity if intensities list is empty
ENH: change orientation convention in ElementArrayStim to match that of other stimuli
DOC: describe orientation convention in BaseVisualStim and ElementArrayStim
Merge pull request #451 from djmannion/master

ENH,DOC: flip ElementArrayStim ori, and document convention
Merge pull request #452 from jeremygray/master

ENH: builder text flip - better tooltip and value checking
ENH: Framebuffer object (FBO) now available. Supports the following...

- avg or add blend modes (for genuine superposition with floats)
- each pixel is now checked for bounds at flip() and converted to blue or
	red noise if above or below bounds
Merge branch 'master' of github.com:psychopy/psychopy
NF: class visual.InstructionScreen

goal = simplify code in coder demos
design pattern = display text, wait for any key, quit on escape
RF: a couple code simplifications, esp rating scale demo