Propagating changes from code.google.com(https://codereview.appspot.com/13536043/).
This is a refactoring to support the addition of another script
needed in the code.google.com repository but not needed in i18n.
Removed out-of-date translation files.
Removed all of the interstitials in Maze mode 2.
Added a cat as an obstacle for the mouse in Maze. Simply replaced one of the random tiles with a cat.
Removed the additional tiles_mouse_2.png
Revert "Removed the additional tiles_mouse_2.png"

This reverts commit d2d3db631ed6dc58e815b7bc9cd2a2826688e76d.
Revert "Revert "Removed the additional tiles_mouse_2.png""

This reverts commit 587222f52cf8d1f21f200193ab821ae3323ad679.
Reverting the mouse changes.
Revert "Added a cat as an obstacle for the mouse in Maze. Simply replaced one of the random tiles with a cat."

This reverts commit 8178ff4535bc74024a6a57a5d802fbe3cea2ca6b.
Added the obstacles in mouse and cheese. The obstacle still shows there is a path, but when you tend to walk on it, it shows as if you hit a wall.
Corrected the description for normalize function in Karel.
Maze starting direction
Karel starting direction
Removed obsolete function displayInterstitialOrCloseModalDialog from common.js and turtle/maze (removed from everywhere).
Added relative width and margin video attributes so video stays confined to the modal dialog.
Removed the redundant code in rending the maze (normalize).
Updating generateXMLForBlocks in common.js to be more readable.
Convert levels form structure of arrays to array of strucures.
Applied Ellen's feedback and added in another variable to add height to the iframe at a slower rate than the blockYPadding.
Removed TODOs from template and cleaned up the text. More to do after Ellen's CL that moves common messages. Pushing this to avoid merge conflicts, and have maze/template.soy better prepared for final changes.