Added 2 histogram formatting code to qiime/format.py and unit test, in preparation for use with new quality_filter_fasta.py code
Resolves issue #1065

Changes the 'simpson_e' calculation to be increase as evenness increases. Reference thread:
https://groups.google.com/forum/#!searchin/qiime-forum/simpsons%2420e/qiime-forum/F7GvTT2Elgw/rU8fnNfLoNMJ
Added another example

Added another test calculation from another ecology lab. Given that the literature definition of this function is unclear, I wanted to have another resource which validates our interpretation.
Changed permissions to 644.
Removed commented line
Remove "versions" from the QIIME overview tutorial

The document was pointing to an FTP site that read "QIIME-1.5.0" and in
turn was confusing users. I've changed this such that there's now a
folder named qiime-files in thebeast.colorado.edu where I've copied the
current contents of qiime/examples/qiime_tutorial/ and updated the
documentation of tutorial.rst.

Fixes #1137
Rename folder to be qiime_overview_tutorial.zip
Fixing formatting on several lines
Fix #1157

Resolve the problem where OTU maps would contain duplicated observation
identifiers and in turn would cause the biom formatter to fail.

The problem was originated because the command being executed was:

    cat otu_map_1.txt otu_map_2.txt otu_map_3.txt >> full_map.txt

I've change this such that the '>>' operator is replaced with '>' hence
overwritting the file named full_map.txt in case it existed i. e. when
passing the --force flag from the script interface.
Fixing more line formatting
Merge branch 'master' into issue_1065
Fixing quoting mistake
Merge pull request #1254 from ElDeveloper/issue_1137

Remove "versions" from the QIIME overview tutorial
Merge pull request #1223 from wdwvt1/issue_1065

Issue 1065
Merge pull request #1261 from adamrp/pick_open_ref_formatting

Fixing formatting on several lines
Merge pull request #1190 from walterst/quality_filtering_code_nov102013

Added 2 histogram formatting code to qiime/format.py and unit test, in p...
Merge pull request #1257 from ElDeveloper/issue_1157

Fix #1157