APT_U: Fixes for GetLockHandle to boot system titles.

- Also added comment to GetLockHandle function.
APT_U: Release service lock on initialization.
APT_U: Set a valid parameter buffer size in GlanceParameter.

- Also Clarified GlanceParameter/ReceiveParameter documentation.
APT_U: Added stub for function AppletUtility.
Add support for UTF-16 strings for LowPaths in FS:USER
Use std::u16string for conversion between UTF-8 and UTF-16, FS:USER functions
FileSys: Added DebugStr method to Path class.
FileSys: Updated backend code to use FileSys::Path instead of string for paths.
FS_User: Support FileSye::Path in a more generic way.
Archive: Fixed close archive before freeing.
Archive: Fixed to not destroy archive handle on close.