Improve fatal messages in raft

Change-Id: I4ebdb9d3bd0ace23f921556e57174b2ee27f9627
Fix net.errClosing

We had a buggy pool logic. This commit simplifies the code and resolves
the issue of re-using closed connections.
Add package docs for connpool
Increase the timeout for server warnings
nit in bee
Merge branch 'master' of github.com:soheilhy/beehive
Fixes conn.Close
Nits in proxy logs
Increase default request timeout to 60 sec
Make go1.3+ client identical to the new stdlib
Nits in sync example
Copy data when collecting messages
Nit in stats
Add buckets as program arguments in kvstore
Add the first version of kvstore benchmark
Merge branch 'master' of github.com:soheilhy/beehive
state: Add HasEmptyTx to Transactional

Change-Id: I9d835a46fcfb037215e85a2f13a7636c81be5ff3
core: mirco-optimization for empty L2 transactions

When there is no state update in a L2 transaction we can sometimes
directly emit L2 messages. This will improve the performance of sync
by 10%.

Change-Id: If1c5868182180dd60de1b3da460ac839d065c6a4
Merge branch 'master' of github.com:soheilhy/beehive
Micro-optimization in sync

Change-Id: I20d3a0a92044d2bcda7dee61cebb56f9273092a0