Before we only had c_utf8_to_locale, but now functionality is needed to
convert a path to UNC before converting it. That does c_utf8_path_to_locale
now, while c_utf8_string_to_locale only converts the plain string, ie.
to generate wide char strings for output.
This enables the calling function to free these accordingly. That is needed
because the makeLongWinPath for efficiency reasons does not always realloc
the original string.
