Openni: update patch sha1.
insighttoolkit 4.6.0

Added SCIFIO module

Closes #1100.
new formula: MADlib 1.6.0.

MADlib: Big Data Machine Learning in SQL for Data Scientists.

MADlib is a library that allows you to apply many statistical
and machine learning algorithms to data that resides in a DBMS
(PostgreSQL).

Closes #1057.
OpenNI2: Fix patch shasum

Closes #1108.
Xylib: new formula.

Closes #918.
stacks 1.20

Add DOI.
cdo: cleanup, use opt_prefix
gmt: cleanup, use opt_prefix
ensembl-tools: reorder PERL5LIB
astrometry-net: use opt prefixes
ucsc-genome-browser 303
gdcm: 2.4.3

Closes #1113.
graph-tool: add support for --with-python3

Closes #1073.