qtdemux: Add support for trick play in push mode

Submitted by man..@..ge.com

Link to original bug (#755381)

Description

Summary:
qtdemux: Add support for trick play in push mode.

Description:

Overview: Currently, qtdemux doesn't support trick play in push mode i.e. Fast Forward(+4X), Fast Backward (-2x,-4x), Slow Forward(+1/2X) and Slow Rewind
(-1/2x).

1.Patch 1 adds support to trick play.

2.Patch 2 is to enable fast rewind in souphttpsrc since its disabled now.

Steps to Reproduce:

1. Play the attached MP4 file.

Actual Results:
Fast Forward(+4X), Fast Backward (-2x,-4x), Slow Forward(+1/2X) and Slow Rewind
(-1/2x) doesn't work in push mode.

Expected Results:
Fast Forward(+4X), Fast Backward (-2x,-4x), Slow Forward(+1/2X) and Slow Rewind
(-1/2x) should work in push mode.

Build Date & Hardware:
Build 2014-12-18 on Ubuntu 12.04

Version: 1.4.5