Disable channel icon scan when icon path is empty

XBMC checks the icon path and terminates the scan early if no path is set. This commit causes the setting to respect that.
Show values of string settings with button controls
remove unload/reload of fonts when init/destroy window, as it's not needed anymore
add infolabel Player.Filename
CurlFile: request UTF-8 as preferable charset
CurlFile: don't set 'keep-alive' as cURL do this internally
Some web servers can't properly handle duplicated header value.
[GUIInfoManager] Add VideoPlayer.AudioLanguage infolabel.
[DVDPlayer] Set CMediaSettings::Get().GetCurrentVideoSettings().m_AudioStream on open/set.
revert 5fd167da1ebf407dcb4afa87d1a3bd5a6d66fedb
[Win32] resolution of namespace std:: conflict for bind()
add audio and subtitle language info to video osd if available
[release] version bump to 13.0 alpha10 as we start new merge window
[win32] Use more VC optimizations for important XBMC parts for 'Release' config
* Enable 'Full' code optimization
* Prefer speed over small size
* Allow any suitable inline function
* Enable Generate Intrinsic Functions
* Enable Function-Level Linking
* Enable 'Whole Program Optimization' for compiler, linker and lib task
* Explicitly enable linker optimization /OPT:REF and /OPT:ICF
[win32] Fix various linker warnings
[win32] Fix win32 VS debugging environment. No need anymore to copy dlls to Debug/Release dirs.
[win32] don't copy .dlls to debug directory
allow repository add-ons to point to multiple add-on repos, versioned by xbmc.addon version.
[cleanup] CRepository FetchChecksum can be static, some other methods const, and there's no need for a critical section.
[cleanup] includes in Repository.h/cpp
[cleanup] drop CStdString from CRepository