Improve hash function
Improve hash function

This is the hash function found in k&r second edition
mixed with djb2 because it uses xor instead of adding.
This new version gets a better distribution of the
symbols in the hash table.

k0gaMSX/scc,k0gaMSX/kcc,8l/scc,k0gaMSX/scc,k0gaMSX/scc,k0gaMSX/kcc,8l/scc,8l/scc