Improved the editor menu controls metrics

- The controls now behave correctly when resizing the window.
- The window has now got a minimum size and is centered on screen.
Add FHS-compliant installation instructions for Linux (fixes #58)
Remove obsolete instructions
Rename OPENDUNGEONS_* variables to use the OD prefix
Fixed the size and centered of the join game window.
Rename last OPENDUNGEONS_* variables to use the OD prefix
Fixed and centered the skirmish loading menu
Fixed and centered the game hosting menu.
Add a desktop entry and icons to be installed in the hicolor theme on Linux
Add translation of the desktop file comments: dansk, deutsch and français
Merge pull request #193 from akien-mga/development

Drop bin suffix on Linux and the launch script (fixes #57)
Merge pull request #201 from Bertram25/development

Fix #198
Fixed the spawn pools in Scream in the Dark skirmish map...

Fixes #195
Remove useless intermediate OD_*_DEST variables
Link icon dynamically (let the system locate it in the hicolor theme) when the CMAKE_INSTALL_PREFIX is /usr
Merge pull request #205 from Bertram25/development

Fixed the spawn pools in Scream in the Dark skirmish map...
Merge pull request #204 from akien-mga/linux-install

Add installation instructions for Linux + some distribution bonus (desktop file, icon)
Add console command to list the animation from an Ogre mesh
Random crash when a goal is completed
fixes #208
Crash when opening levels with maplight indicator twice
fixes #207
Crash when creating a room owned by a factionless seat in the editor
fixes #196
When using training room, creatures sometimes go through wall (same on hatchery)
fixes #185