Elim. need for cgutils.inbound_gep and OpaqueType

These were additions to numba only present in the impala branch.  Now that we're depending on the master/devel branch of numba, they are eliminated.
Added string functions capitalize() and split()

String split works in at least one case (see the test fn).

Also added some copyright headers, and rejiggered utilities and precompiled fn usage.