tetrix in Scala, an html5 book

I rebuilt tetrix in Scala series that I wrote last year into an html5 book using @n8han's Pamflet. I went through the git history commit by commit and upgraded the libraries and toolset to the state of the art as of 2013. This means multi-project build.sbt using sbt 0.13.0, Scala 2.10.2, every specs2 specs interpolated, and Akka 2.2.1 loaded on Android using pfn/android-sdk-plugin 1.0.6.

In addition, an extra day 13 was added for debugging and tuning up tetrix on Android.