Smarter Makefile

No longer fizzbuzz specific - now can just do `make blah` and `make
test-blah` for any blah.rs.
Add targets to run things
Managed boxes
Owned boxes
Got tired of seeing all the generated files
Borrowed pointers
Simple version of DwemthysArray
Dwemthys using enum
Simple match example
Simple vector example
Simple mutability example
Further vector mutability example
Simple generics
DwemthysArray using traits
Guessing game.
Better guessing game