[stdstring] get rid of CStdString in PVRDatabase, PVRGUIInfo, PVRManager
[stdstring] get rid of CStdString in pvr/addons
[stdstring] get rid of CStdString in pvr/channels
[stdstring] get rid of CStdString in pvr/recordings
[stdstring] get rid of CStdString in pvr/timers
[stdstring] get rid of CStdString in pvr/dialogs
[stdstring] get rid of CStdString in pvr/windows