h264parse: Fix multiple SEI messages in one SEI RBSP parsing.

An SEI RBSP could contains more than one SEI message as specified in
7.4.2.3.1.

This commit change the parser API: the gst_h264_parser_parse_sei()
function now create and fill a GArray containing GstH264SEIMessage.

https://bugzilla.gnome.org/show_bug.cgi?id=721715
codecparsers: refactor common nal parsing to nalutils

Moves common code from h264 and h265 to a separate file
tests: h264parse: fix tests after leading 0x00 removal

Commit 6af387cd5ab2c946025e5499903e75ee87b063a9 made h264parse
strip a leading 0x00 byte from some output scenarios. This broke
tests as bs_to_nal test expects one more byte on the output.

Fix this by comparing the output with the expected stripped version,
too.
mxfdemux: Don't go into pull mode when the sequential flag is set

When the scheduling query results has GST_SCHEDULING_FLAG_SEQUENTIAL set
in its flags don't go into pull mode to prevent over-eager seeking.

https://bugzilla.gnome.org/show_bug.cgi?id=722934
androidmedia: Don't handle FLUSHING or NOT_LINKED as error

And also just stop the task for FLUSHING.
mpegts: install but nodist for generated header
tsdemux: Fix flags comparison operator precedence

Fix operator precedence, so the whole operation is
negated instead of only flags variable.

https://bugzilla.gnome.org/show_bug.cgi?id=722096
codecparsers: Don't use gst_ as prefix for private symbols

Otherwise they get exposed/accessible in the resulting .so

And make check-exports will complain
opencv: The plugin works with 2.4.8 too

https://bugzilla.gnome.org/show_bug.cgi?id=723230
uridownloader: Always release the object lock in gst_uri_downloader_fetch_uri_with_range()

even if downloader->priv->urisrc is not set. This avoids deadlock under some
some conditions on cancel.

https://bugzilla.gnome.org/show_bug.cgi?id=723127
tests: camerabin: improve preview handling in tests

Always erase the preview image data to allow the next check for
it to operate properly
Automatic update of common submodule

From d48bed3 to 1a07da9