Added INNER JOIN to all queries to accommodate the &queries=<>
stuff.

Added support for querying custom:
      Basically query the db for all custom
      attrs with the uri. Check to see if the
      usr wanted that returned, if so append it
      to the dictionary.
Added lots of comments on functions to explain what they do.
Also fixed an issue where the object scope attributes query string
was wrong and always tried to compare against the account URI instead
of the domain specific URI.
Started to add test cases for the metadata server.
Only on attributes queries now.
Added unit tests for object and container crawlers that covers
retreiving the meta data from respective sources.
Crawler format function updated to correct default values
that we support
Completed test cases for Attributes section of the metadata server
Tests:
for each scope
    for each attributes (object, container, account, mixed)
Testing the PUT method as well
Added comments to the test case funcs
Added LICENSE to files that didn't have them
Fixed pep8 errors in crawlers and backend/server
Still some more to fix pep8. and unused imports
still need to be taken care of
Fixed a lot of PEP8 and flake8 errors
Lots of imported but not used are fixed
Lots syntax styling fixed
Merge branch 'osms-queries' of https://github.com/ucsc-hp-group/swift into osms-queries

Conflicts:
	swift/metadata/backend.py
	swift/metadata/utils.py
	test/unit/metadata/test_backend.py
Merge branch 'osms-queries' of https://github.com/ucsc-hp-group/swift into osms-queries

Conflicts:
	test/unit/metadata/test_backend.py