Unpause (if applicable) when going to DVD menu
[rbp/omxplayer] Support ff/rew

Big missing feature added for Pi.
It works by increasing the clock and discarding audio when at 2x and 4x.
For rewind and 8x and higher, it uses a different scheme. It pauses video, and single steps.

For both schemes it uses the normal dvd player mechanism of seeking when the clock has diverged by too much.

Notes:
dvdplayer still decodes (then discards) audio when ff/rew.
I'm skipping the decode step (too much cpu at 4x realtime).

I've made GetTime return m_clock.GetClock() when ff/rew. (m_State.time is too jumpy).
renderer: drop old texture done event for gles
[skin.confluence] add description textbox (ID 6) to SettingsCategory.xml
Merge pull request #2958 from Montellese/settings_description_confluence

[confluence] add settings descriptions to GUI
[lang] update of internal addon language files
[lang] update of core language files
[lang] update of skin.confluence language files
[lang] fixed: empty msgid entries
Merge pull request #2956 from davilla/drop-texturedone-event-for-gles

renderer: drop old texture done event for gles
[win32] - fix crashing with libnfs 1.6 by bumping to 1.6.1 (which is 1.6.0
+ a compile fix - 32bit time_t define was missing in the release target of
vs project for libnfs)
Merge pull request #2954 from jmbreuer/upstream-dvdmenu

Unpause (if applicable) when going to DVD menu
Merge pull request #2955 from popcornmix/ff_rew

[rtbp/omxplayer] Support ff/rew
[osx] - don't steal the hw volume keys. Those are controlled by osx and should always be. This reverts part of 6bb569c as we already did in the frodo branch. And now all nyxboard users say booo and go away ;)