orbitcpp module created

[Murray Cumming <murrayc usa net>]

I have started the orbitcpp module. It's basically just the
orbit-cpp-head branch with the C stuff removed, plus:

- Mark's changes to make it install the idl compiler backend library and
export a function for ORBit2 to call.
- I have renamed .hh files to .h, because they no longer need to be
clearly separate from the C files, and it is inconsistent with the rest
of *mm.

This doesn't work yet, as you can see in the tests:

orbit-idl-2 -l c++ ./../test.idl
orbit-idl-2 2.4.3 compiling
  mode, show preprocessor errors, passes: stubs skels common headers
skel_impl imodule


** (process:29462): WARNING **: ./../test.idl compilation failed

-- 
Murray Cumming
murrayc@usa.net
www.murrayc.com