add apps factory and test it.
refine the docstring processing and add facebook, dropbox, github.
add more apps from the example source.
test linkedin and fix up the deep copy issue.
refine docs.
fix up the python 3.x compatible issue.
fix up the python 2.6 compatible issue.
Add contributor in code file:
https://github.com/lepture/flask-oauthlib/pull/94
Add @stianpr in author list
Changelog for 0.5.0. Version bump to 0.5.0