Added new option type: 'multiple_choice'
Returning choices as list and modifying alpha_diversity.py to use the new option type
Adding my name to credits
Adding import for OptionError
Basework for changes to otu_cat_sig so that you can sweep through directories, and collate or not collate the results
Update README.md
script can now accepted an input dir or input file, if input dir, the user has the option to collate the results into a single file, or produce a results file for every table in the passed directory. Specifying an output directory is now a required paramater to avoid confusion.
Changed @ElDeveloper's style suggestions
Added new usage example for input directory
Added qiime.simsam.create_replicated_mapping_file.

Also added unit tests.
Added docstring.
Added -m/--mapping_fp option to simsam.py.
Existing unit tests now pass.
Added mention to ChangeLog.

Fixes #784.
Added default to -m/--mapping_fp option help text.
Removed unnecessary imports at beginning of script
Updated ChangeLog.md to reflect additions to otu_category_significance for @gregcaporaso
Merge pull request #786 from jrrideout/issue-784

Added -m/--mapping_fp option to simsam.py
ported code from a fork of my gregcaporaso/microbiogeo repo

never actually merged that fork into microbiogeo as it makes more sense for this code to be in QIIME
added myself to the credits