Kexi/Main Window/Full screen

• DONE
• Wish #298880
• Target milestone: 2.5

Full screen is going to be used with small screen computers, namely netbooks etc. There going to be two different modes implemented but called from different places in the UI.

• Kexi MainWindow fullscreen:
  • Decorations will be hidden
  • Tabbar will be hidden
  • Will get called using F11
• Tab (part fullscreen):
  • Single KexiWindow fullscreen:
  • Hiden everything except Current KexiPart.
  • If in design mode, have design tabs auto hide to the top.