Compatibility with push-based bud (see test/ts_sriram.rb for tests that pass)

1. Changed @budtime -> budtime (since imported modules are wrapped by their own bud_instance objects), and only the toplevel bud_instance is the real engine.

2. Removed backports. Bud works on 1.8.7 and above

3. Timing fixes, by having some tests sleeping a little before proceeding, to
   allow a bud instance running in the background to do what it needs to do.

4. tc_voting: Expect aggregated "accum" results to be in any order.

	modified:   bfs/bfs_client.rb
	modified:   bfs/datanode.rb
	modified:   bfs/hb_master.rb
	modified:   cart/disorderly_cart.rb
	modified:   delivery/dastardly.rb
	modified:   ordering/assigner.rb
	modified:   ordering/lamport.rb
	modified:   ordering/nonce.rb
	modified:   paxos/leader.rb
	modified:   paxos/prepare.rb
	modified:   test/tc_2pc.rb
	modified:   test/tc_dastardly_delivery.rb
	modified:   test/tc_heartbeat.rb
	modified:   test/tc_kvs.rb
	modified:   test/tc_lamport.rb
	modified:   test/tc_reliable_delivery.rb
	modified:   test/tc_voting.rb
	new file:   test/ts_sriram.rb
	modified:   voting/voting.rb
New invalidation scheme means that scratches are lazily erased on demand, which
means one cannot assert their emptyness.
	modified:   test/tc_reliable_delivery.rb
Merge branch 'master' into push-runtime

Conflicts:
	cart/disorderly_cart.rb
Remove traces of backports.
Tweak test suite structure.

Introduce a common file "test_common.rb" that loads rubygems, bud, test/unit,
and sets up the load path correctly. This is useful cleanup, and necessary so
that Ruby 1.9.2 and newer can run the test suite.
Whitespace cleanup.
Merge branch 'master' into push-runtime
Remove two-phase commit code.

Per Peter A., this is crufty and busted. We should checkin a new implementation
in a little bit.
Merge branch 'master' into push-runtime

Conflicts:
	test/tc_2pc.rb
	test/ts_sandbox.rb
	test/ts_sriram.rb
ruby 1.9.3 compatible changes, and working with push-runtime 1a4352..

bfs: "chunk" is a reserved word in Enumerable; replaced with chnk
membership:  "local_id" changed to "my_id" for uniformity

	modified:   bfs/bfs_client.rb
	modified:   bfs/chunking.rb
	modified:   bfs/data_protocol.rb
	modified:   cache_coherence/mi/mi_cache.rb
	modified:   cache_coherence/mi/mi_protocol.rb
	modified:   membership/membership.rb
	modified:   ordering/nonce.rb
	modified:   ordering/vector_clock.rb
	modified:   test/tc_kvs.rb
	modified:   test/tc_leader.rb
	modified:   test/tc_mi.rb
	modified:   test/tc_multicast.rb
	modified:   test/ts_sandbox.rb
	modified:   tests.rb
Merge remote-tracking branch 'sriram/master' into push-runtime

Conflicts:
	test/ts_sandbox.rb
	tests.rb
Removed 2pc
	modified:   test/ts_sandbox.rb
	deleted:    test/ts_sriram.rb
	deleted:    tests.rb
Push-bud compatible changes

	deleted:    ../2pc/2pc.rb
	modified:   ../README
	modified:   ../bfs/bfs_client.rb
	modified:   ../bfs/datanode.rb
	modified:   ../bfs/hb_master.rb
	modified:   ../cart/cart_protocol.rb
	modified:   ../cart/destructive_cart.rb
	modified:   ../cart/disorderly_cart.rb
	modified:   ../kvs/kvs.rb
	modified:   ../ordering/assigner.rb
	modified:   ../paxos/leader_election.rb
	modified:   ../paxos/prepare.rb
	modified:   cart_workloads.rb
	modified:   kvs_workloads.rb
	deleted:    tc_2pc.rb
	modified:   tc_assignment.rb
	modified:   tc_besteffort_delivery.rb
	modified:   tc_bfs.rb
	modified:   tc_carts.rb
	modified:   tc_chord.rb
	modified:   tc_dastardly_delivery.rb
	modified:   tc_demonic_delivery.rb
	modified:   tc_e2e_bfs.rb
	modified:   tc_heartbeat.rb
	modified:   tc_kvs.rb
	modified:   tc_lamport.rb
	modified:   tc_leader.rb
	modified:   tc_leader_election.rb
	modified:   tc_member.rb
	modified:   tc_mi.rb
	modified:   tc_multicast.rb
	modified:   tc_mv_kvs.rb
	modified:   tc_mvcc.rb
	modified:   tc_ordering.rb
	modified:   tc_reliable_delivery.rb
	modified:   tc_timers.rb
	modified:   tc_vector_clock.rb
	modified:   tc_voting.rb
	new file:   test_common.rb
	modified:   ts_sandbox.rb
Reenabled tests tc_besteffort_delivery:test_besteffort_delivery and tc_ordering:test_group_nonce

	modified:   tc_besteffort_delivery.rb
	modified:   tc_ordering.rb
Code cleanup for disorderly cart.
deprecate Assigner code, add AggAssignPersist and comments, change interface names
Update voting sandbox code for accum() semantic change.

Now returns a Set, not an Array.
Merge branch 'master' of github.com:bloom-lang/bud-sandbox
Code cleanup for voting tests.
Minor code cleanup.