properly identify boolean variables

[SpaceWalkerRS]

they are currently given the int type

[zeichenreihe]

I don't know much about the problem itself, but my JVMS (Chapter 4) knowlede suggests, that this is also a problem for shorts and chars.

[SpaceWalkerRS]

I started fixing this in the first 2.0 alpha build, it's not perfect but it seems it catches most cases.