Work on the project structure

I must have rewritten almost anything concerning project structuring. Well,
Makefile.build is used, datatypes got their own directories, etc. etc. pp.

I will continue with some programming style and interface issues which will
certainly break any backwards compatibility and then update the version to
the next nibble.

The third will be to actually write some good sample modules with the
improved and working-so-far engine after these steps.

I don't really want to bother listing everything I did. Suffice it to say
that compatibility is not to be assumed.