ibec_RenameFile attempts to change the name of the file specified by OldFile to NewFile.
If the operation succeeds, RenameFile returns True. If it cannot rename the file (for example, if a file called NewName already exists), it returns False.
This function now supports Unicode (UTF8) file names. You can still use ANSI names, necessary checks and conversion are performed automatically
function ibec_RenameFile(OldName : string; NewName : string) : Boolean;