New Blocking behavior is implemented in the Client and Replica side.
Semaphore object is changed accordingly.

---TODO---
- Fix other objects when we decide this approach is the right
way to go.
- When the client "blocks", it keeps sending messages to the Leader,
creating traffic. Is this acceptable? Maybe a real "blocking" behavior
would be better.
Merge branch 'master' of ssh://git.systems.cs.cornell.edu/opt/git/paxi
Very unstable, full of debugging.
Latest changes to the connection.py. The code has debugging to do. Right before we add the new receiver thread.
New Receiver Thread added.
Last push after thread changes.
socket debugging
Fixed git conflicts
more socket debugging.
Lock in connectionpool, timeout in select added
deleted ports
moved all sends out of the receiver thread
Removed all debugging.
New Evaluation numbers. Counting Semaphore for receivedmessages.
Changes to the paper.
New tests, about scalability and failure.
New numbers and files are added.

The code is changed slightly.
More changes to the paper.

Also, we are using CrossTex.
abstract
half-pass through the intro