Imported Upstream version 1.3.1+git20140512~de7e5e48
Merge tag 'upstream/1.3.1+git20140512_de7e5e48' into launchpad

Upstream version 1.3.1+git20140512~de7e5e48
Updated d/changelog with new development snapshot
Configure: allow GStreamer 1.3.1
Set environment variables to search in /opt/gstreamer1.4

PATH, PKG_CONFIG_PATH, LD_LIBRARY_PATH and DEB_SHLIBDEPS_INCLUDE.
Build with GStreamer 1.4 snapshot
Build as GStreamer 1.4 for parallel installation with the system version
Install into /opt