Add package opusfile

Opusfile is a decoder for Opus files. It provides a higher-level API
than the opus library, of which it makes use.

Update function taken directly from opus.mk. Two patches are needed to
make it work, one is taken from the upstream repository (change
introduced after the latest release), the other is by myself.
Merge pull request #159 from uklauer/opusfile

Add package opusfile
package freeimage: add -lws2_32 to pkg-config file
Merge branch 'stable'
Mention new member of core team: Martin Gerhardy
Merge branch 'stable'
Adjust year of copyright notice
Merge branch 'stable'
update packages mpfr gcc-mpfr
update package vmime
package qtbase: cherry-pick upstream sql fixes

Qt 5.0.2 should be out one of these days anyway, but in the meantime
it's nice to have these fixed.
update package sqlite
update package libgcrypt
json-c downloads have moved to Amazon S3 (see https://github.com/json-c/json-c/issues/72)
Merge pull request #160 from residuum/master

Official json-c downloads have moved
add package opencv

OpenCV (Open Source Computer Vision Library) is an open source computer vision and machine learning software library.

See more: http://opencv.org/about.html
Merge pull request #164 from lsaavedr/add_opencv

add package opencv
Mention mxe-octave in the docs
Merge branch 'stable'
package opencv: disable gtk, gstreamer, and xine since they are unix only