omxil: Add an omxil_vout module
omxil: Try to load the broadcom OMX IL core

This requires loading a separate host library first.

The host library is not unloaded, since it starts background
threads when initialized, and the deinit function does not stop
the threads. Therefore, this library cannot be unloaded once
loaded and initialized.
omxil: Hardcode known roles for OMX broadcom components
omxil: Change the signalled OMX version to 1.1.2

The broadcom OMX IL core requires this in order to respond to
requests.

This shouldn't probably break other OMX cores, unless they are
picky about it in the same way, requiring version 1.1.1.
omxil: Use larger input buffers to the decoder

The default ones on the raspberry pi aren't large enough for higher
resolution content.
omxil: Switch to the alternative OMX ABI, used on the raspberry pi

This breaks usage of the omxil decoder with any other OMX core - this
cannot easily be switched at runtime since it affects how structs
are laid out.
omxil: Add Broadcom specific OMX headers
omxil: Include broadcom specific indexes in OMX_Index.h
omxil_vout: Add broadcom specific calls