Added Cracker Tester Folder

The stringrpc code in Cracker Tester/stringrpc works as is. I just run
"make -f Makefile.linux" and it compiles and runs. The files in Cracker
Tester are all automatically generated from cracker.x using "rpcgen -a
-C cracker.x" I renamed the automatically generated files
cracker_client.c and cracker_server.c to client.c and server.c
respectively to be able to use the prof's Makefile.linux. Finally,
Makefile.linux has been edited from the stringrpc Makefile.linux simply
by substituting strings. with cracker. When I run "make -f
Makefile.linux" I get no errors except undefined symbols for
_xdr_uint8_t