Automatic update of common submodule

From dbedaa0 to d48bed3
po: update for autogen changes to fix build
Make git ignore test driver files
configure: make make dist output .tar.xz files

Like all other modules
Fix gstglconfig.h-related 'make distcheck' issues

Fix srcdir vs. builddir issue in docs and 'files left after
disclean' issue for gstglconfig.h
memory: provide copy_into_texture
mixer: give access to the pads at render time

allows us to move the video frame mapping somewhere else
filter: handle capsfeatures properly
mixer: handle 0/1 framerate better in caps
Bump gstreamer requirement to 1.2
mixer: unmap the video frames we map

plugs a memory leak
filter: a little code cleanup
testsrc: use _context_get_gl_api
glupload: Remove texture scaling artifacts from the TEXTURE_RECTANGLE -> TEXTURE_2D transition

fixes the funky colours in some of the yuv formats

https://bugzilla.gnome.org/show_bug.cgi?id=721155
configure: fix libjpeg check

We were setting HAVE_JPEG=no JPEG_LIBS=-ljpeg if libjpeg wasn't found. Unset
JPEG_LIBS too so that linking doesn't fail.
deinterlace: fix texture coordinates computation

Fixes a regression introduced by fffdcbdd3dde437e10cf6e1b5e40c6958d41e6c1

https://bugzilla.gnome.org/show_bug.cgi?id=720826
use GstContext for GstGLDisplay propogation

implements the hooks required in GstElement::set_context and the context query
display: remove _{set,get}_context

A GstGLDisplay doesn't need a GstGLContext and its use
was cause a reference cycle
use the allocation query to propogate GstGLContext

uses the GstVideoGLTextureUploadMeta api type for the query
upload: add support for GstVideoGLTextureUploadMeta