add builtin to set GUI Language
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.
Use different names for USB/CEC and Udev related threads

While debugging some rescanning issues, it helped to distinguish the different PeripheralBus threads. Since there is a limit to thread names, I had to make sure the name fitted into 15 characters.

This is part of a series of PRs: #2323 and #2541

Before:
```
xbmc.bin-+-{EPGUpdater}
         |-{EventServer}
         |-2*[{PVRClient}]
         |-{PVRGUIInfo}
         |-{PVRManager}
         |-2*{PeripheralBus}            <-
         |-{SoftAE}
         |-{TCPServer}
         |-5*[{XBPython}]
         `-8*[{xbmc.bin}]
```

After:
```
xbmc.bin-+-{EPGUpdater}
         |-{EventServer}
         |-2*[{PVRClient}]
         |-{PVRGUIInfo}
         |-{PVRManager}
         |-{PeripBusCEC}                <-
         |-{PeripBusUSBUdev}            <-
         |-{SoftAE}
         |-{TCPServer}
         |-5*[{XBPython}]
         `-8*[{xbmc.bin}]
```
added ActivateScreensaver to builtin functions
[textlayout] move setting of defaultColor into ParseText
[textlayout] move addition of '\n' for the last line into LineBreakText
[textlayout] remove ParseText wrapper that's only used once
[textlayout] add UpdateStyled() for updating with pre-styled text
[textlayout] adds SetStyledText to CGUILabel
[textlayout] perform text styling directly in CGUILabelControl to simplify code
[OSX] support CMD+v to paste clipboard text.
[DVDPlayer] ffmpeg support http/https protocol options, also fix #14309.
[DVDPlayer] Take advantage of if evaluation order.
[DVDPlayer] Remove unnecessary NULL check.
changed: Improve/cleanup logging when seeking cached streams
Remove unneeded or outdated _MSC_VER macro #ifs
fix ; wake-on-access ; wait for specific net-interface to get connected
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