added cython brute force pair coutning routines.
Merge remote-tracking branch 'upstream/develop' into develop
Merge pull request #7 from duncandc/develop

Develop
After pushing my own code that included table_bundle features to my own fork,
I fetched and merged with upstream/develop BEFORE merging Duncan's pull request
that fixed the hard-coding of the CATALOG directory in test_make_mocks.

Merge remote-tracking branch 'upstream/develop' into develop