Started using git. Contains files. Able to view first .tif image in set
loaded after 'Load Data' is clicked.
Added multithreading and image caching to reduce load times.
Merge https://github.com/mik854e/pyxda

Merged with Mike. Added new user interface and directory trait.

Conflicts:
	pyxda/rawviewer/display.py
	pyxda/rawviewer/handler.py
	pyxda/rawviewer/loadimages.py
	pyxda/rawviewer/pyxda.py
	pyxda/rawviewer/ui_pyxda.py