kill off 'primitives'

[GoogleCodeExporter]

I believe some dead code related to (LangEval.hs) 'primitives' can go away and 
pretty much of old stuff that hinges on it, i.e. 'parserPairs', 'fuse', 'melt', 
etc.

The new mechanism does not need the declaration with "primitive" any more for 
values as they are registered with their types from the code directly.

Original issue reported on code.google.com by ggr...@gmail.com on 18 Aug 2011 at 5:00