DOC: Fix group_significance.py Sphinx issues

Fixes #1467 #1615.
DOC: fix remaining Sphinx errors in doc build
MAINT: remvoing tests for supported versions for python packages. these are outdated, incomplete, and redundant (as the versions are already reported here)
ENH: version information for sumaclust and sortmerna now included, fixes #1735
BUG: split_libraries_fastq.py --phred_offset no longer ignored

Fixes #1656.
BUG/DOC: fixed bug, and cleaned up some docs while I'm at it
Remove lanemask requirement from qiime config, store lanemask in qiime.filter

Related to #1696.
Merge pull request #1761 from gregcaporaso/issue-1735

updates to print_qiime_config.py
Remove qiime.quality imports

:woops:
Remove lane mask from test_ampliconnoise.py
DOC: fix capitalization
DOC: add ARB reference to qiime.filter.get_lane_mask

Based on Phil Hugenholtz's suggestion by email.
Merge pull request #1763 from jairideout/bug-fix-party

Bug fix party!