* add many missing declarations to sections
* GstController has been removed, update docs
* skip GstIndex when generating documentation
* rephrase so gtkdoc doesn't imagine return value
* add missing argument description for gst_context_new()
* document GstOutputSelectorPadNegotiationMode and move to header-file
https://bugzilla.gnome.org/show_bug.cgi?id=719614
Adds getcaps/setcaps to output-selector and adds a property
to select which type of negotiation should be done.
The available modes are:
* none: no negotiation (current behavior), getcaps return ANY and
setcaps aren't set on any of the peers
* all: use all pads (default), getcaps returns the intersection of
peer pads and setcaps is set on all peers
* active: getcaps and setcaps are proxied to the active pad
https://bugzilla.gnome.org/show_bug.cgi?id=638381
