adding the send-template call
setup: pull long_description and license from README and LICENSE files.

Ensures info on PyPI matches version being distributed there. (Avoids problem where docs on github are ahead of published version on PyPI.)
Tests: break apart tests.py into tests directory
readme: add info on contributing
Support sending attachments
Readme: Note Mandrill silently filters unsupported attachment types
(Readme rst * escapes)
Merge pull request #22 from brack3t/attachments

Support attachments
Merge branch 'send-template' of git://github.com/peillis/Djrill into send_template
Tests: add ability to check which Mandrill API endpoint was used.

Add DjrillBackendMockAPITestCase.assert_mandrill_called; use it in representative backend test cases.

(Also make get_api_call_data work with various ways of calling requests.post.)
Add send-template tests (and fixes).

Add test cases for send-template.
Expand template_content dict into Mandrill's name/value array.
Don't send template_content as "None" if missing.

Clean up some variable names in the backend.
Readme: docs for send-template

(and break up the lengthy 'usage' section)
Readme: Explain using multiple email backends
Exception cleanup

Introduce djrill.NotSupportedByMandrillError for unsupported functionality (previously used generic ValueError).
Change to djrill.MandrillAPIError, derived from requests.HTTPError, for API error responses (previously used djrill.mail.backends.djrill.DjrillBackendHTTPError -- retained as equivalent for backwards compatibility).
Raise NotSupportedByMandrillError for unsupported attachment mimetypes.
Move MANDRILL_API_URL to package root (out of backend)
Handle bcc as Mandrill bcc_address, rather than additional to address
Readme: clean up "Django EmailMessage Support" section
Readme: restore summary (from old long_description)
Travis: re-enable Python 3.2 testing

(Recent requests updates may have fixed Python 3 setup issues)