Added 2 histogram formatting code to qiime/format.py and unit test, in preparation for use with new quality_filter_fasta.py code
Adjusting formatting in split_libraries_fastq

Line lengths adjusted, indentation adjusted, use of "is" and "is not" when
doing comparisons with None. Changed a try-except to use dict.get function.

Fixes #1251
Fixes issue with emtpy tables if data points are missing. Fixes #1197
Test catches raised error when data points are missing. Fixes #1197.
Modifications and test additions to resolve issue #1160
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.
Fixed script usage test
Fixed contrib
Modified test and function.

There is an untested function in this code that makes boxplots. The build failed because that function called the modified function from the previous commit.
Stylistic fix
Merge branch 'master' into issue_1160
Merge branch 'master' into issue_1160
Merge branch 'master' of https://github.com/qiime/qiime into issue1251
Add a new line

Fixes #1251
Merge pull request #1190 from walterst/quality_filtering_code_nov102013

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

Fix #1157
Merge pull request #1253 from adamrp/issue1251

Adjusting formatting in split_libraries_fastq
Fixed script usage strings
Move blastall fp check to full install class