abyss 1.5.1
maker: Add the DOI of MAKER2
maker: Add license info to caveats
ucsc-genome-browser 299
picard-tools 1.113

Closes #870.
edirect: update sha1sum
alembic 1.5.4

Closes #403.
oce: remove X11 dependency

OCE does not use X11 on Mac OS X.

Closes #856.
opencv: switch eigen and openexr to optional

Eigen and OpenEXR are special-case (interoperability) libraries and
are not needed for general purpose usage of OpenCV.

Closes #874.
igraph 0.7.1

Closes #878.