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
display: remove _{set,get}_context

A GstGLDisplay doesn't need a GstGLContext and its use
was cause a reference cycle
use GstContext for GstGLDisplay propogation

implements the hooks required in GstElement::set_context and the context query
use the allocation query to propogate GstGLContext

uses the GstVideoGLTextureUploadMeta api type for the query
fail in context query response if display is NULL

allows tee's in the pipeline i.e.
videotestsrc ! tee name=t ! queue ! glimagesink t. ! queue ! glimagesink
upload: add support for GstVideoGLTextureUploadMeta
Remove texture scaling artifacts from the TEXTURE_RECTANGLE -> TEXTURE_2D transition

fixes the funky colours in some of the yuv formats
glmem: report successful copy to the caller