Brute Force create and kill MathText

to kill asteroids: self.killAsteroids()
to kill mathText: self.killMathText()
delete useless empty lines
Everything but Check marks are killed()

Only thing left to kill is the check marks from correct answer.
Everything now killed when you go to the portal

The only thing that will not be killed is tombstone
create and kill MathText no longer brute force

Use Gabe and Sean's suggestion to recreate MathText creation and killing
function
Added more images and Scenes for tutorials

Added some more images and created the tutorial scenes
add tutorial images
add skip button in tutorial
fixed story text displayed in tutorial
Level cleared sound added
Added feedback when level has been cleared
Added a thumbs up image
Fixed a bug Black hole landing on player
[not important]
add mini game right after levelclear screen.

dont know how to start a new full  level game yet.  so there will be an
error when answered the mini game question at second time.
killed enemy now respawn after 10 second

also minor bug fixed when recreate MathText
add mini game right after levelclear screen.

dont know how to start a new full  level game yet.  so there will be an
error when answered the mini game question at second time.
Reward with one laser for every 3 right answers

change the indention of def asorbAnswer(self)
[not important]
bug report update