Revert "Make the ShareJS based client work on the Android device"

This reverts commit a3770b492fb8feb5e3389a6ad7a3d8677ce0ab33.
Revert "Add minimal working version of ACE based code editor."

This reverts commit 24120cf109a1ccb34791d25ebd2d21c7018f9242.
Revert "Replace code textview with a WebView + TextArea."

This reverts commit 627a6adf0e2fafbb261c5ad33ba7733dccc7908b.
Revert "Only support tablets"

This reverts commit a74913819a68ab7422f06f0a353d8c5a54c8b7da.