Update API documentation

- Remove template.md.reference placeholder
- Add draft API documentation from Ward Harold. See his email for
  details:
  http://lists.us.dell.com/pipermail/crowbar/2013-March/002877.html
Remove trailing whitespace from API documentation
Update REST API documentation

- Rename cbapi.md -> README.md
- Rename attribapi.md -> attrib.md
- Rename barclampapi.md -> barclamp.md
- A bunch of edits, mostly formatting
Merge pull request #1760 from jamestyj/api-draft

Add Ward Harold's REST API draft to docs