mpegtspacketizer: Convert PCR times to GStreamer times before comparing them against 500 * GST_MSECOND

Otherwise it will believe to detect PCR gaps already when there's a very small
gap of a few milliseconds, breaking playback of some files.
Revert "mpegtspacketizer: Convert PCR times to GStreamer times before comparing them against 500 * GST_MSECOND"

This reverts commit 9f186c6ab32c1e949916d385186b2d400190add6.

That commit was actually completely wrong, nevermind.
mpegtspacketizer: Store PCR time/byte offsets in 64 bit integers

32 bit integers are going to overflow, especially the PCR offset to
the first PCR will overflow after about 159 seconds. This makes playback
of streams stop at 159 seconds as suddenly the timestamps are starting
again from 0. Now we have a few more years time until it happens again
and 64 bits are too small.
glupload: don't determine if frame needs upload by pointer compare

https://bugzilla.gnome.org/show_bug.cgi?id=734269
GstGLWindow, GstGLImagesink, x11: Scale navigation events on resized windows

If window is resized, GstStructure pointer values have to be rescaled to
original geometry. A get_surface_dimensions GLWindow class method is added for
this purpose and used in the navigation send_event function.

https://bugzilla.gnome.org/show_bug.cgi?id=703486
ext:faad: Set rank to SECONDARY as the libav decoder is concidered better

https://bugzilla.gnome.org/show_bug.cgi?id=676131
glvideomixer: add a background property

That's compatible with the compositor/videomixer property

https://bugzilla.gnome.org/show_bug.cgi?id=731954
dashdemux: support downloading segments in reverse order

When a seek with a negative rate is requested, find the target
segment where gstsegment.stop belongs in and then download from
this segment backwards until the first segment.

This allows proper reverse playback.
dvbsrc: push stream-start after successfully tune/lock op
dvbsrc: dvbbasebin: add 'tune' signal

It works the same as the 'tune' property that is used only to signal
the element that it should tune, but it is more natural to be used
as a signal rather than a property.

It is also proxied at the dvbbasebin element
dvbsrc: drop gst_dvbsrc_retry_ioctl for retry macro

LOOP_WHILE_EINTR macro makes it easier to handle
assorted ioctl argp types. Functionality is otherwise
equivalent.
dvbsrc: wrap around known-interruptible ioctls

Also get rid of the asumption that some requests like
FE_SET_TONE or FE_SET_VOLTAGE only error out with -1
dvbsrc: get rid of remaining trailing whitespace
dvbsrc: parsechannels: read DVB-S freq in kHz