[Libreoffice] [PATCH][REVIEW] IDL @since build error if not OOo

[Laurent Godard]

Hi all

here is a patch (master branch) that add "LibreOffice" and "LO" string
support to @since tag in idl files

this solves a build breakage in odk if an IDL @since tag in offapi
contains LibreOffice or LO

Laurent