Set of small features to make starting new development easier

I've made a small set of changes to manifest and customization to make starting new development easier. There is short list of changes:

 - added ability to set minSdkVersion (defaults to 9, because from games/most multimedia apps point of view nothing important changed from that API level, some even say it's API 8, but 9 is safer assumption due to some bugs in 8 that needs special workarounds)
 - added ability to set main game class name (I found out that I always change that, so why not allow to customize it during project creation?... default still is MyGame)
 - moved proguard configuration to file so people does not have to hack build.scala, and added $package$.** to it
 - made application debuggable by default
 - fixed version difference between manifest and build.scala (0.1 vs 1.0)
 - changed default name from "Game" to "My Game" to highlight possibility of spaces in name. It isn't obvious at first where they are possible and where not, so subtle hint like that is good solution I think.

I believe those make starting new project even easier, especially for new users (and we must agree, that Scala for Android unfortunately still isn't established solution).

And of course, thanks for great work on this project, it really was best starting point for my developments after looking at multiple solutions!