because glade catalogs don't allow : in widgetnames
which blocks making a catalog for our custom widgets
Change-Id: I3d590ce7451264b49fa5a82a752dac44e47bbd81
Under Linux dlsym will search other locations and find them if they exist
elsewhere, but not under windows, so its easy to put the wrong lib name in if
developing under Linux because it'll generally work anyway.
So add a script: bin/verify-custom-widgets-libs which can be used under Linux
to verify that the required factory methods exist in the right lib.
Change-Id: Ic30f8da5acc4712684a7a25fbfb003e8b21cb867
