Optimized the MessageCracker class.

MessageCracker.Crack() now uses a compiled delegate instead of
MethodInfo.Invoke(). This results in runtime performance comparable to
that of a direct method call. No units tests were added because no
public interfaces were changed. Also, existing MessageCracker tests
pass.
trivial whitespace cleanup
Merge pull request #234 from connamara/cracker_opt_125

Optimized the MessageCracker class (cherry-picked a commit from #125)