introspection: Assorted minor introspection and documentation fixes

https://bugzilla.gnome.org/show_bug.cgi?id=732534
basesink: reset QoS on segment event

This avoids spurious warnings about slow machine when upstream
sends new segments without flushing.
identity: Proxy the accept-caps query

We always work in passthrough mode so there's no point in doing
something more clever in basetransform. Also the basetransform
code leads to problems with incomplete caps and downstream
elements that use GST_PAD_FLAG_ACCEPT_INTERSECT.

https://bugzilla.gnome.org/show_bug.cgi?id=732559
pad: Don't unlock while iterating over all sticky events for removal

Otherwise we might end up getting the event removed from elsewhere
at the same time while we're unlocked for g_object_notify().

https://bugzilla.gnome.org/show_bug.cgi?id=732556
tests: don't use post-GLib 2.32 API in bufferlist test

g_ptr_array_insert() is GLib >= 2.40
message: Work around g-i/pygobject/gjs bug with ~0 in enums

GST_MESSAGE_ANY was considered a long by pygobject and gjs, and thus
couldn't be used in gst_bus_poll() and similar APIs as they expect an
int-typed enum.

Just use 0xffffffff instead for now.

https://bugzilla.gnome.org/show_bug.cgi?id=732633
tools: suppress GLib warnings when gst-inspecting deprecated properties

GLib in git will spew a g_warning() when a property marked as
deprecated via param spec flags is accessed. Suppress this by
setting the appropriate environment variable.
gst-uninstalled: add video and base library paths from -bad

https://bugzilla.gnome.org/show_bug.cgi?id=732770
tests: fix locking in gstpoll unit test

The mutex needs to be locked when g_cond_wait*() is
called.
libs: gstcheck: init and clear global mutex and cond variables
libs: gstcheck: check that mutex is locked before g_cond_wait*() is called

Sanity check to catch problems in unit test.
fdsrc: fix error setting when uri is invalid

Elements should always set the GError
docs: There is no decodebin2 anymore, don't pretend otherwise
docs: Cleanup interface references in docs

 * Delete references to removed interfaces
 * Add missing documentation sections
 * Fix duplicate interface references for GstDevice

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=732786
docs: Fix documentation typos and inconsistencies

 * GstGlobalDeviceMonitor was renamed to GstDeviceMonitor
 * Expand GST_MESSAGE_DEVICE to the full enum value names
 * Correct the incorrect references to the GstDeviceProvider interfaces
 * Describe caps arguments for gstcheck interface
 * Add missing docs for GstNetAddressMeta and its add function
 * Add docs for toc helper macros
 * Avoid refering to GstValueList type as done elsewhere

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=732786
po: Update translations
Update .po files
Release 1.3.91
gst: init taglist gtype to use it in gstvalue

Otherwise it will have a 0 value and GstTagList won't be found
for GstValue functions (serialization/deserialization)

https://bugzilla.gnome.org/show_bug.cgi?id=733131
debugutils: Unref pad template after use

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=733121