Added support for Joins and M2M, fixed some bugs.

Fixed bug that would produce errors when String() was called twice on
the same query object.

Added IncludeOffset helper that includes the result offset in the query.

Added InnerJoin helper that includes an inner join expression in the
query.

Added some helper methods and parameters around returning column names
and fields as quoted vs. unquoted, absolute vs. relative.

Added reflect helpers to automatically construct M2M table names and
field lists, as well as interact with those tables.
Fix documentation typo and add helper method.

Added helper method for getting quoted fields for a M2M table, and
updated a typo in the documentation.
Test coverage for new M2MQuotedFields.

Added a test for the new M2MQuotedFields helper function.
Remove cover profile.

Oops. No reason for that to be in the repo.
Add cover.out to .gitignore

Prevent future accidental commits.
Merge pull request #8 from DramaFever/paddy_m2m_reflect

Added support for Joins and M2M, fixed some bugs.