Fixed bug with splitting OTU tables.

If the category to split on had state(s) in the mapping file but not in the OTU
table, the script would fail. This happened when trying it out on the full
dataset.
Fixed bug when suppressing OTU category tables.
Merge pull request #40 from jrrideout/misc_fixes

Miscellaneous fixes
Added unit test for get_personal_ids().

Also rewrote function to be a little more concise.
Added tests for create_personal_mapping_file().

Also changed create_personal_mapping_file() to return new mapping file data instead of writing to an output file so make testing easier.
updates to default prefs file

new colors incorporated (issue #41) and bug fixed (issue #42)
Merge pull request #43 from gregcaporaso/prefs-updates

updates to default prefs file
fix for issue #44
replaced test_data/pref.txt with newer version
renamed to highlight that this prefs file is project-specific
Merge pull request #45 from gregcaporaso/issue-44

fix for issue #44
Added test for create_alpha_diversity_boxplots_html
Added test framework for create_personal_results()

Still need to add more tests for this function, but a framework is now in place
to create/delete temporary input and output.
Added more tests for create_personal_results().
refined parsing of otu_cat_siginificance to only return the body site. Added tests to test_format.py
Fixed bug in script refactor.
modified to address issue #46
Merge pull request #47 from jrrideout/issue_38

Added unit tests, more refactoring, and some minor cleanup of code.
updated some text
additional work on the text describing results