Fix docstrings as suggested by @cdeil
Add __all__ to modules
Fix astropy inter sphinx link for building docs with 0.3.1

Closes #45 but can be removed once astropy 0.4 is released
Fix intersphinx links
Update astropy intersphinx to those used in 0.4
First attempt at documentation landing page
Add documentation stubs and draft of ccddata
Wrap paragraphs
Add combiner API to index
Document Combiner clipping
Draft image combination docs
Attempt at a travis workaround

until astropy helpers is fixed...
Add a setup tools travis hack
More edits to combiner docs
Small start on cosmic ray documentation
First complete draft
Fixed several broken links and other errors found by @cdeil and @bsipocz
Fix several broken links

Thanks again to @cdeil and @bsipocz
Make all doctests pass
Merge pull request #69 from mwcraig/docs

Thanks everyone for the feedback!