PVR: Resolve channel dummy in GUIWindowPVRTimerSettings

When using Backend channel number , use channel unique ID member instead channel number
PVR: Cosmetics in GUIWindowPVRTimerSettings
CFile: fix null pointer dereference in Stat() and Write()
[vfs] CFile: add null pointers checks
videodb: add SetDetailsForMovieSet
jsonrpc: add VideoLibrary.SetMovieSetDetails
adds left, top, right, bottom, centerx, centery to the list of xml nodes that can take constants
support positioning dialogs via <left> and <top>
ensure library:// folder URLs have slash at end
Merge pull request #3534 from Karlson2k/cfile_fix_01

CFile: fix null pointer dereference
File: declare and implement class auto_buffer
File: replace CAutoBuffer usage with auto_buffer, fixes memory allocation check
File: add 'LoadFile' function and copy code from FileUtils
CFile::LoadFile: replace ugly reference to pointer with auto_buffer
FileUtils::LoadFile: replace implementation with call of CFile::LoadFile
[vfs] CFile: fix: close underlining file implementation in destructor
Merge pull request #3556 from Montellese/jsonrpc_setmoviesetdetails

jsonrpc: add VideoLibrary.SetMovieSetDetails
CharsetDetection: add new header 'CharsetDetection.h' and implementation 'CharsetDetection.cpp' with function GetBomEncoding()
CharsetDetection: add XML charset detection functions
XBMCTinyXML::Parse: return 'bool' instead of 'const char*'
Return value is (rarely) used only as bool