[darwin] - add method for detecting if we are sandboxed on ios - use this new method in DarwinHasVideoToolboxDecoder
- add method DarwinGetXbmcRootFolder - returns <home>/Documents if we are sandboxed (this allows the user to access everything needed via itunes file sharing). If not sandboxed - behave like before (e.x. <home>/Library/Preferences on jailbroken installations)
[ios] - use DarwinGetXbmcRootFolder for determining the directories during init
[ios] - enable itunes filesharing (only works on sandboxed installation/deployment via xcode)
[osx/ios] - fix wrong path was shown onscreen (ios/atv2) when debugging was enabled use the new method DarwinGetXbmcRootFolder from darwinutils here too
[ios] - if a dev sets a real code signing identity in the xcode project our last buildstep will ensure that the whole app with all binaries is signed in a way that it can be deployed to unjailbroken devices (xcode itself misses alot during signing because it doesn't know the *.viz, *.pvr, *.so binaries ;) ).
[ios] - adapt ios readme with instructions on how to deploy on non-jailbroken devices via xcode
[cosmetics] - remove commented code
Merge pull request #3437 from Memphiz/iossandbox

[iOS] - Adaptions for developing for XBMC on non-jailbroken devices
CLangInfo: fix loading of languages after 92214e362b1b73f9f3629a5e8686709b6191e3dc
we don't save the value of lookandfeel.skintheme/skincolor with the .xml extension (anymore)
settings: fix value update of string settings depending on the value of another string setting (fixes #14648)
fix pydocs contents