Adds the Create Game screen subtitle

[BdeBock]

Fixes issue #2233
Adds a subtitle to the create game screen in singleplayer and multiplayer game.

[GooeyHub]

Can one of the admins please verify this patch?

[Cervator]

Thanks!

You might look into playing with Git Rebase next, to avoid merge commits like that :-)

It is done clean enough to where I can merge this OK as-is, but if you try it out and get it working feel free to apply it for this PR, it'll be a bit before I can grab it.

@GooeyHub add to whitelist

(The build will likely be unstable, a few tests have broken, known issue)

[GooeyHub]

Refer to this link for build results (access rights to CI server needed):
http://jenkins.terasology.org/job/TerasologyPRs/500/
Uh oh, something went wrong with the build. Need to check on that

[GooeyHub]

Refer to this link for build results (access rights to CI server needed):
http://jenkins.terasology.org/job/TerasologyPRs/501/
Uh oh, something went wrong with the build. Need to check on that