BF: ElementArrayStim was not updating its position using setFieldPos
BF: Resizing warning message needed new form glob_vars

When the stimuli got split into separate files the global variables broke
because they're only global within a file.
BF: logging messages were sometimes duplicated and weren't showing new vals
BF: allow unicode log messages to be sent to terminal by encoding
DOCS: bumped version number for release 1.80.04
BF: Some (but not all) greyscale images were being misinterpreted by PIL

Some were being detected as RGB and some left as L which was then
causing errors in type conversions.

Force all to be greyscale if alpha mask and force all to RGBA if image/tex

Conflicts:

	psychopy/visual/basevisual.py
	psychopy/visual/image.py
BF: further fixes to greyscale image stims, including numpy arrays

These should be processed as gl.floats and then colored, which wasn't
working correctly
TEST and BF: some greyscale images were still not coloring correctly if no shaders

Conflicts:

	psychopy/visual/basevisual.py
ENH: For now let's not keep sending the user errors about TextBox
BF: re-inserted the requirement of wx 2.8 only, while we make sure 3.0 is OK
BF, TESTS: fix visual.BufferImageStim, make visual tests

- switch to inherit from ImageStim, remove _tex code
- add visual tests and .png's

Conflicts:

	psychopy/visual/bufferimage.py

Jeremy had removed tex as a property here, but it had also been altered.
I've gone with the removal. (jwp)