Fixed the error in make_3d_plots.py caused by ANOVA update.
Fixed errors thrown in core_diversity_analysis.py.
removed qiime_test_data/otu_category_significance
Fixed longitudinal correlation problems

Addressed problems with how longitudinal correlations were being calculated and reported.
Made minor updates to imports and documentation.
Made major updates to qiime/otu_significance.py to facilitate longitudinal gradient calculation.
Merge branch 'ocs_collab' of https://github.com/wdwvt1/qiime into ocs_collab
Modifications to resolve test failures

compare_alpha_diversity.py depended on incorrect fdr correction procedure. Modified to resolve the failures. BH step procedure was removed from compare_alpha_diversity.py since it would necessitate large changes in the overall functioning of the script that will need to be completed at a future date.
otu_gradient_correlation.py was modified to add functionality, though discussion about mathematical correctness of the longitudinal correlation feature is ongoing.