re-entrant version of the Twofish extension
Added twofish extension twofish2tcl.c with reentrant code using a hash table with the
engine's name

twofish.so is just for Linux x68_64

All the other files are full of debug lines!

Cleaning will be set after version: Handles with commands
added "delete" option to the Twofish extension and and "destructor" to
the alternate cbc and ebc implementation so that deleting an
object by Itcl will delete the hash entry and the allocated structure
Merge branch 'pre160' of github.com:zdia/gorilla into pre160