Abtracted the innards of lldb-core away from the SB interface. There was some

overlap in the SWIG integration which has now been fixed by introducing
callbacks for initializing SWIG for each language (python only right now).
There was also a breakpoint command callback that called into SWIG which has
been abtracted into a callback to avoid cross over as well.

Added a new binary: lldb-platform

This will be the start of the remote platform that will use as much of the 
Host functionality to do its job so it should just work on all platforms.
It is pretty hollowed out for now, but soon it will implement a platform
using the GDB remote packets as the transport.

llvm-svn: 128053