saner Makefile and tweaks to _oasis
a simple policy
make tests run without running core tests
a topology that helps debug fast failover
async: Increase file descriptor limit for async

The file descriptor limit seems to be set to 1024 by async. This commit
makes katnetic use a different entry point for the scheduler, which
allows the user to configure the maximum number of file descriptors.

Related to frenetic-lang/ocaml-openflow#70.
final-async: Raise the limit of pending connections to 64 instead of the default 10.
Merge branch 'final-async' into experiments

Conflicts:
	INSTALL.txt
	_oasis
	examples/diamond.kat
	setup.ml
	test/NetKAT_Test.ml