game: implementing main menu

* refactored scene/script stuff - we now have level
  object that encapsulates both
* main menu is a special level without RUBE part
* implemented 3 layered parallax in main menu
game: implementing main menu

logo and menu items with selection added
game: implementing main menu

episode picker added
game: implementing main menu

level picker added, now able to launch level1 from
menu
game: introduce UI component

we transform UI phased component into
separate UI component that has 'zOrder' property
and a separate 'render' method. this solves 2 problems:
* layered UI components like pause menu UI above game UI
* flicker when changing between UIs, i.e. when 'update' handler
  is used both for render and logic there can be situation that
  half of interface is already rendered and decision is taken to render
  something else, it'll then be rendered right on top of current UI
game: pause mode implemented

game can now be paused
game: pause menu implemented
game: dialog fast complete

when we don't want to wait until all this
chattin' ends
game: input updated

* able to simulate touchscreen with a mouse
* proper 'ok' handling for touchscreen
game: implementing touchscreen support in menu
game: implementing touchscreen support in menu
game: implemented touchscreen support in menu
game: android updated