gl/upload: avoid performing color conversion when there is no need

One such example is when the buffer contains GstGLMemory in the
RGBA format

https://bugzilla.gnome.org/show_bug.cgi?id=729278
gl/convert: clobber alpha channel when needed

Needed in the conversion from padded RGB formats to formats with an
alpha channel.  e.g. BGRx -> ABGR, etc

https://bugzilla.gnome.org/show_bug.cgi?id=729742
gl/upload: update the video info on mapping a video frame

The buffer should contain the most specific data on how the data is
formatted.  We should use this information.

https://bugzilla.gnome.org/show_bug.cgi?id=729896
gl/upload: set out_tex after reset, not before

Fix a regression introduced recently with the lazy init.
It was happening when calling gst_video_gl_texture_upload_meta_upload
from an aplication. So not using gst_gl_upload_perform_with_buffer.
dashdemux: initialize the mutex and cond for fragment download
mssdemux: remove uridownloader in favor of internal source

Refactor mssdemux to remove uridownloader to use an internal
source element which reduces startup latency and provides smaller
buffers for better buffering management downstream
mssdemux: measure bitrate similarly to hlsdemux

new bitrate = (old bitrate + (last fragment bitrate * 3)) / 4
mssdemux: deprecate unused max-queue-size-buffers

There is no internal storage of buffers anymore
mssdemux: reenable segment tracking for streams

Store the latest pushed timestamp so that mssdemux streams know
where they are in time
mssdemux: Always accept the latency configure event

Upstream or internal elements are irrelevant and we should
always succeed.
mssdemux: handle error messages from internal source

set up a bin message handler to get notified of error messages from
the internal source element
mssdemux: fix caps leak
mssdemux: avoid deadlocking when erroring

It might get stuck when posting the message while
a reconfigure event is being pushed upstream
glupload: Correctly update video info in upload fallback

When the upload accelerated method fails, we fallback to an upload,
but the video info was not correctly updated.
glupload: Correctly update the video info from video meta

Using gst_video_info_set_format() isn't complete when updating
a video info from video meta.
glupload: Ensure we still have a texture after upload_set_format()

gst_gl_upload_set_format() resets the upload, hence the texture.
So we need to ensure we have a texture after this call when
uploading.
asfmux: Don't leak bytereader

By making it go through the error path that takes care of cleanups

CID #1212168
jp2kdecimator: Don't leak various slices and arrays

CID #1212139
CID #1212140
CID #1212141
mpegpsmux; Fix stream leak

CID #1212164
sdpdemux: Don't leak adapter data

CID #1212158