fixing the navigation between windows
Merge branch 'zusehub-ios' of https://github.com/ZuseApp/zuse-ios into zusehub-ios
Fixed a few bugs.
Improved functionality of the grid size slider.
Fixed a small bug with the grid slider animations and modified “done” option in group view controller to be a checkmark instead.
Fixed a transition to the sprite editor when the grid slider is showing.
Added support for correct project size in canvas.  Won’t load a project unless it’s the correct size.  A side effect of this is that the examples won’t run on the 3.5” phones.
Modified the tutorial skin and added a toolbox without a point.  Test script up to the end of laying out the canvas.
Removed border around tooltip during tutorial.
Fixed a bug in the canvas transition animations.
Add map/filter to traverser, exclude placeholder data

Realized I just need collection functions on recursive code
structures, so re-implemented ZSCodeTraverser methods
in terms of reduce and felt like a LISP god. We now exclude
code with #placeholder symbols that the user doesn’t fill in.
Handle division by zero and type coercion

Refactored code so that it’s data-driven instead of a bunch
of if/else statements. Might be wise to refactor all the code
to behave this way. Also added type coercion for all
expressions. I may be missing some. Divide by 0 now
divides by 1. Not sure the best way to handle that.
Generator view almost done, collisions and generation now working.
Adding Pods directory for happiness and freedom.
New app icon in all sizes for iPhone.
Merge pull request #75 from cliftonite/master

New app icon in all sizes for iPhone.
Buttons are less wonky now.
Create README.md
Update README.md
Property access can now be delegated out to the renderer, x and y are now accurate when read.