Modified INSTALL file to be current.

Note: I plan on reformatting in Markdown format and renaming this file
INSTALL.md in the near future.
Bumped copyright year.
Fixed broken setup.py (it's dabo.__version__ now).
Moved long dabo module docstring to README.md

Took the long docstring in dabo.__init__.py, reworded and reformatted
it lightly in Markdown format, and put it in README.md.