ffmpeg: update to 2.1.3

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
ffmpeg: delete some useless configure options

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
ffmpeg: enable gnutls

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
libbluray: update and fix update script

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
ffmpeg: update to 2.1.4

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add documentation of `make update-checksum-*`

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add documentation of `make update-package-*`

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Add documentation of `make update-checksum-*`

Signed-off-by: Timothy Gu <timothygu99@gmail.com>
Merge pull request #333 from TimothyGu/stable

ffmpeg and libbluray updates and fixes
Merge pull request #334 from TimothyGu/stable-s

Add documentation of `make update-checksum-*`
Merge branch 'stable'

Conflicts:
	index.html
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