Merge pull request #24 from duncandc/develop

Develop
Added empty columns to galaxies table for purpose of mock_observables development
Merge pull request #25 from aphearin/develop

Added empty columns to galaxies table for purpose of mock_observables development
working on delta sigma code
Minor modifications to API of read_nbody to improve behavior of test suite.

Now, the ask_permission boolean governs whether the user is prompted for permission
to download the halo/particle catalog.
Merge remote-tracking branch 'upstream/develop' into develop
Beginning to revamp read_nbody. Currently committed version is likely broken.
Hacked the astropy utils code to create some configuration utilities.

There are now a few global directories where halotools data is stored,
all of which are subdirectories of the astropy cache directory. So the
code is now becoming more closely intertwined with astropy.
Deleted unnecessary methods from Config object
Continuing reconfiguration of catalog management system
Added method to identify best matching catalog in cache
Still working on processed_snapshot object in read_nbody. Hardest parts are now done.

Should create methods to read from (and create, when necessary) 'halos' and 'particles'
subdirectories of the halotools subdirectory. This is where I should store my
pre-processed data.

Also still need to finish writing the 'halos' and 'particles' methods
of the processed_snapshot object. Once that's done, read_nbody will pretty much be in business.
Added cosmocode modules
Merge pull request #26 from BenediktDiemer/develop

Added cosmocode modules
Narrowing in on completing the catalog manager and revamping read_nbody.
Nearly done with processed_snapshot object in read_nbody
Improvements to UI of the catalog manager
Added method to load catalogs into memory from explicit filename input
Convenience attributes added to Catalog_Manager object
Minor modifications to API of load_catalog method of Catalog_Manager