version 1.78 endless glide mode/score

In 'glide' game mode, added the ability to fly through a 'portal'(looks like a large slow-spinning red ball) to the next random level. After flying through a portal, the player score will be sent to the 'GlideHigh_201712' leaderboard with scoring ending when the player crashes. So to set a score for one level, don't fly through any portals - to set a score across multiple levels, keep flying through portals. Also added a beginning basic 'choice' menu at the game start between 'Climb' and 'Glide' - the other modes(crystal hunt and explore) are available also, just from the same pause menu as earlier.