build failure: Menu is ambiguous

[Pim Vullers]

Trying to build strip I get the following error:

make -j5
[ 9%] Generating ScaleWithBubble.c, Strip.c, ComicLayout.c, ImageManipulator.c, ComicBook.c, ComicPage.c, TopDisplay.c, StripWindow.c, FileHandler.c, Resources.c, Resources.vapi
/var/tmp/portage/pantheon-extra/strip-9999/work/strip-9999/src/ScaleWithBubble.vala:155.11-155.14: error: `Menu' is an ambiguous reference between `GLib.Menu' and `Gtk.Menu'
  private Menu menu;
          ^^^^
/var/tmp/portage/pantheon-extra/strip-9999/work/strip-9999/src/StripWindow.vala:78.3-78.6: error: `Menu' is an ambiguous reference between `GLib.Menu' and `Gtk.Menu'
  Menu menu = new Menu();
  ^^^^
Compilation failed: 2 error(s), 0 warning(s)
make[2]: *** [src/ScaleWithBubble.c] Error 1
make[1]: *** [src/CMakeFiles/strip-comicreader.dir/all] Error 2
make: *** [all] Error 2

This should be easily fixed by using Gtk.Menu or GLib.Menu instead.

[Pim Vullers (pimvullers)]

The related branch fixes the build issues and removes the using statements according to the coding standards.