[WIN32] prepare mingw build files for jenkins.
[WIN32] removed old mingw build files.
ffmpeg: bump version to 2.2
[depends] add --with-platform=raspberry-pi switch
ffmpeg: change depreciated functions avcodev_alloc/free_frame
ffmpeg: change depreciated attributes qscale, qstride
vaapi: change depreciated get_buffer, release_buffer
vdpau: change depreciated get_buffer, release_buffer
dxva2: change depreciated get_buffer, release_buffer
[linux] log how ffmpeg was linked, ffmpeg version check and logging
[osx] specify target-os as 'darwin' for osx/ios, and amend sed to be compatible with BSD
[osx] support building with depends ffmpeg instead of internal
[cosmetic] drop unused variable
[osx] drop deprecated get/release_buffer
[ios] fix build
[depends] add neon and tegra switches
[depends] add m4 macros for compiler flag testing
Merge pull request #4608 from Montellese/gui_slider_cleanup

CGUISliderControl: some cleanup and fixes
Merge pull request #4606 from Montellese/upnp_fixes

upnp: some fixes
Merge pull request #4596 from Montellese/jsonrpc_properties

jsonrpc: expose specialsortseason and specialsortepisode for episodes