Added: Possibility to toggle 24-hour clock in the top menu.
Change: Restart is now Shift+F10 instead of only F10.
Change: Toggle adviser is now Shift+A instead of only A.
These three implement Mark's patch in 1449.

Change: Key combinations will only trigger if that exact combination is pressed. I.e. Ctrl+R will not trigger R too. 

Please try these changes out and check so that things still work as intended.

-- Notes to developers --

onKeyDown and onKeyUp:
Fix: buttons_down was not reset for normal keys.
Fix: Keyhandlers were not handling Ctrl correctly anymore (at least on Windows) since rawchar is some other character than the pressed one, e.g. Ctrl+R is something like the newline character.

git-svn-id: http://corsix-th.googlecode.com/svn/trunk@2250 c39591fa-788f-11de-a72b-d90af8dea425