Increase USB and CEC rescan interval to 5 seconds

In one of my investigations to see why XBMC performance is so bad (even when idle) I found one of the threads (in my case PeripheralBusCEC) scan a big sysfs tree recursively. On the 1Ghz AppleTV 1 device this would be about 2% of the CPU *every* second. For the USB thread we luckily have Udev events, but for CEC it is using sysfs polling which is quite expensive. It would be better to make use of Udev as well for CEC (where available) however 5 seconds should be fine for everyone.

In my own builds I even brought it down to 30 seconds. Which means 29 seconds of reduced CPU usage.

The CEC polling probably should be more restricted to specific sysfs sections, or preferably use Udev as well, when available.

PS XBMC needs a special idle-state where it can turn down these expensive threads to make sure hardware can go into deeper sleep states. Especially for devices that doesn't do suspend for various reasons this is a requirement. (The ATV1 device for instance gets warm even when idle) If we can combine display-sleep with low-power states and a less expensive main-loop, that would be already quite an improvement without needing a complete refactoring of the code.
settings: add description textbox (ID 6) to CGUIWindowSettingsCategory
[rbp/omxplayer] Ignore video stream in audio filetypes

Since the ffmpeg 1.2 merge, we fail to play audio file with artwork.
These show up as having a mjpeg video stream, with just one frame in.
We get stuck in buffering and don't play the audio.

As people expect the paplayer behaviour, we ignore the video stream for
audio filetypes, so the audio can play with visualision.
remove unused LinuxTimezone.h include
settings: fix timezone-related settings visibility and default values
settings: fix loading of platform-dependent settings definition files
settings: allow appliance.xml to overwrite runtime-dependent visibility conditions and default values
[rbp/omxplayer] Make m_omx_render an object rather than pointer

Seems no reason for it not to be like other components, as it makes merging with command line omxplayer more difficult
[rbp/omxplayer] Remove commented out code
[rbp/omxplayer] Move openmax pipeline creation into portsettingschanged code

OpenMAX setup becomes more straightforward when components and tunnels are initialised after the first portsettingschanged message.
You get one of these after the first frame is decoded (and also when settings change, like resolution).
Doing the setup here means you know useful information about the stream, like the resolution and you avoid having to disable/enable multiple ports.

It will also make creating a pipline with the deinterlace component possible *after* the decoder has identified if stream is interlaced
[rbp/omxplayer] Support automatic deinterlace correctly.

Previously there was no distinction between deinterlace being automatic and force on.
Both did a hack parse that only worked (sometimes) for h264. Other codecs would always force on.

This change now handles the three modes correctly. Off and force on do as expected.
Automatic now queries the openmax video codec, which can reliably determine if a stream is interlaced
Merge pull request #2800 from popcornmix/ignore_video_in_audio

[rbp/omxplayer] Ignore video stream in audio filetypes
Merge pull request #2801 from popcornmix/automatic_deinterlace

[rbp/omxplayer] Support automatic deinterlace correctly
Merge pull request #2637 from dagwieers/rescan-interval

Raise USB and CEC rescan interval to 5 seconds
Merge pull request #2775 from Montellese/settings_description

settings: add descriptions area to CGUIWindowSettingsCategory
[rbp/omxplayer] Remove unused variable m_pTempOverlayPicture
[rbp/omxplayer] Remove unused Pause/Resume functions

These should be implemented with clock component
[rbp/omxplayer] Remove call to OMXLateCount that will be removed
[rbp/omxplayer] Remove unused clock code
Merge pull request #2799 from popcornmix/cosmetics

[rbp/omxplayer] [Cosmetics] Remove unused code