Renames the translations files to their proper names

It's the way they are called in the code.
Makes it extract and compile and load translations

Several fixes to make it work. Now they are correctly handled.
Update translations
Adds .desktop translations support

It works now the same way as an LXQt app. Although it continues to be an
pure Qt App. There's no LXQt dependency.

There's no need to write a line like this:
	Icon=@CMAKE_INSTALL_PREFIX@/share/pixmaps/obconf-qt.png
The CMAKE_INSTALL_PREFIX isn't necessary, the icon engine will find it.
Fixes the app icon install location

Although LXQt patched QIcon engine search /usr/share/pixmaps, native QIcon
doesn't. obconf-qt is an pure Qt app, so we can't rely on LXQt QIcon.
The proper solution is to install it to hicolor/48x48/apps. That's what's
the hicolor theme is for.
Adds .gitigore