update to 0.10.20
changes:
Add the Presets interface
Use the binary registry by default
Deprecate gst_element_get_pad and don't use it anywhere any more.
Reverse playback fixes
API to get missing element messages from parse_launch parsing.
Fixes in latency calculations
BaseTransform negotiation fixes
New Buffering query and messages
Fix multiqueue deadlocks when changing limits
Remove pre-generated parser hacks and require newer flex/bison
Use GSlice in more places
Use static strings in property declarations everywhere to save memory
allocations
Fix unaligned memory accesses with the binary registry and add CRC checks
Lots of other bug fixes

(drochner)