[FFe] Re-introduce indicator-sound-gtk2/ido-gtk2

(Similar to Bug #1044442)

Hi ubuntu-release,

Indicator-sound upstream dropped support gtk2, it means no panel using gtk+2 can use indicator-sound. It's the case for Xubuntu and Lubuntu which uses a gtk+2 panel.

The goal is to re-upload another source package of indicator-sound with only gtk+2 binaries, to not have a regression since previous releases. There were several #ifdefs for Gtk+2 vs. Gtk+3 in the code. They were dropped in favor of Gtk+3 in indicator-sound, so indicator-sound-gtk2 basically does the opposite, apart from that it's identical.

Indicator-sound needs ido ("libido", don't force me to make bad jokes, I make enough of them already), which, in spite of the fact that it's a library and therefore was supposed to keep gtk+2 support for quantal, doesn't build its gtk+2 variant anymore. So I've been forced to reintroduce a gtk2-only version as well to be able to build indicator-sound-gtk2. There were several #ifdefs for Gtk+2 vs. Gtk+3 in the code. They were dropped in favor of Gtk+3 in ido, so ido-gtk2 basically does the opposite. I also had to drop Gtk+3-only widgets (the ON-OFF switch), but there has never been an ido Gtk+2 release with them included, so no API change should be needed. Apart from that it's identical.

It's a temporary solution, until the panels of Xubuntu and Lubuntu have been ported to gtk+3.

Thanks.