added gmp and mpfr sources
Revert "added gmp and mpfr sources"

This reverts commit f4872b4d6c2a57597444482f99823170095cf47d.
Merge branch 'master' of github.com:hitchiker42/SciLisp
miscellaneous stuff to do with bignums and keyword symbols

I think I've finished the creation routiens for bigints and bigfloats

I've decided to use a hash table for keyword symbols, so I only have one
of any keyword and they can be compared rather efficiently.