Adding emacs backup files to .gitignore.
Splitting out header definitions from internal.hpp.

There are now per-class definitions rather than all in one header.
Fixing NULL_PROCESSOR constant (lacked cast).
Fixing interaction with Eiffel runtime.

Marking enter/exit from GC-able sections, passing along
a proper Eiffel object to start a new thread, and extracting
the pid from the varargs of the routine that will start
one the newly spawned thread to recover the initiating object.
Initializing processor list, and root processor.
Actually logging call in call_on.
Filling in a few more macro functions.
Removing some unneeded -D defines from Makefile.