add package openblas

based on: http://hg.octave.org/mxe-octave/file/default/src/openblas.mk
doc update: add GNU Licenses FAQ
doc update: add legal notes

from a long time ago:
http://lists.nongnu.org/archive/html/mingw-cross-env-list/2011-03/msg00107.html
doc update: add GNU Licenses FAQ
Merge branch 'stable'
package blas: tidy up build rule
doc update: add gpatch to OSX requirements

closes #335
package hdf5: enable shared builds and detection of pthreads and zlib
package libgomp:enable shared builds
package openblas: enable openmp and dynamic arch
package xmlrpc-c added.
package xmlrpc-c: switch to github downloads, enable static builds, and disable server components
curl-config must be in PATH when building