arpack.rb: comment correction.

Closes #778.
octave 3.8.1
octave.rb: used Formula["openblas"] per lml suggestion
octave.rb: Made OpenBLAS optional instead of recommended
octave.rb: --enable-jit instead of --disable-jit
octave.rb: brew audit; native graphics fix; readline fix
octave.rb: turned off native graphics by default; added caveats for GUI+native graphics; suppressed some warnings.
octave.rb: fixed the caveats output; removed :x11 dependency; preliminary HEAD support
octave.rb: further cleanup of HEAD support, caveats
octave.rb: --HEAD fixes
octave.rb: restored depends_on :x11
octave.rb: bring back dotwrp prerequisite

This should fix some of the BLAS-related failures for now. An Octave patch is in the works.
octave.rb: add dotwrp dependency for newer OS's
octave.rb: still another vecLib fix
I should have known better than to edit this on github.com before testing
octrave.rb: returned to sane BLAS settings
octrave.rb: returned to sane BLAS settings
Further BLAS cleanup; new caveat
Removed dotwrp dependency for good
Improved BLAS caveat