guile prolog benchmark

[stefan]

Hi, I've come pretty far in writing a parser for prolog. It's a PEG
parser without packrat and interestingly it is done by doing a simple 
modding of a more standard match construct. The parser is custamizable
and it is pretty easy to add new user operators for prolog as you can in 
e.g. gnuprolog.

I did a new test with the famous n-queens example and here are the current 
performance statistics

gprolog WAM             350ms
gprolog COMPILED        100ms
moddeed guile           630ms

I find this quite reasonable and when we add naitive or JIT compilation it
should be fairly easy to take advantage of this as well for the modding I
have done.

Have fun
Stefan