Use typedefs instead of macros for pVM*

They are not as straighforward, but seem to be semantically preferable.

- removed unnecessary forward declaritions, by being complete in ObjectFormats.h.

- introduce pcVM* typedefs that mark the value pointed at as constant

Signed-off-by: Stefan Marr <git@stefan-marr.de>
Turn UNTAG_INTEGER int INT_VAL macro

With the new macro definition, we avoid much of the code duplication. That's how it should have been done from the beginning...

TODO: replace macro by always inlined function to improve debugging. And figure out why untagging needs the check, in best case all not tagged integers are just big integers
Signed-off-by: Stefan Marr <git@stefan-marr.de>
Whitespace

Signed-off-by: Stefan Marr <git@stefan-marr.de>