decodebin: add missing 'time' word to debug message

It prints the buffers, bytes and time limits, but 'time' was missing
from the string.
pbutils: discoverer: Always set the pipeline back to NULL after an error

Otherwize the pipeline would be in an wrong state and on the next
iteration any kind of error could happen

Everytime an error happens in a pipeline the application has to set the
pipeline back to NULL instead of READY.

https://bugzilla.gnome.org/show_bug.cgi?id=733976
check: Fix include path of rtp checks

Fixes make distcheck
Makefile: Add usage of build-checks step

Allows building checks without running them
streamsynchronizer: don't unset DISCONT flag

Unsetting DISCONT flag means we need to copy the buffer. This copy operation
mandates that all GstMemory should be copy-able which is not always the case

https://bugzilla.gnome.org/show_bug.cgi?id=727409
playbin: Keep a reference to the playsink sinkpads

Otherwise playsink might get shut down without us noticing
that our pad references are gone now.

Probably fixes https://bugzilla.gnome.org/show_bug.cgi?id=733165
appsrc: Make caps set action queued together with buffer

https://bugzilla.gnome.org/show_bug.cgi?id=729760
appsrc: Some minor fixes and cleanup
oggdemux: Unref peer pad after use in error case

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=734350
tests: Add missing unrefs of objects after use

Unreffing the objects returned by gst_bin_get_by_name() and
gst_pipeline_get_use() were missing in several tests, so add these.

Fixes https://bugzilla.gnome.org/show_bug.cgi?id=734359