tcp: use correct tx id when sending conn reply

This fixes a bug reported by Rob Stewart. The conn reply contained
the sender's (server's) tx id when it should have been the receiver's
(client's) tx id.

Since the app does not have the connection yet, the socket is empty and
there is no chance of losing a message marker, we can send the reply
from accept() and skip progressing the conn.

Also, add more debug when getting an event.
tcp: return EMSGSIZE when a send is too large

instead of EINVAL.
Prep for 0.1b3 release
API: RMA requires a valid connection on both sides

CCI's disconnect is a local operation. The peer is not notified.
If the peer holds a formerly valid RMA handle and attempts to use
it after the local side has called disconnect, the RMA should fail
with CCI_ERR_DISCONNECTED.
Merge pull request #33 from CCI/topic/disconnected-rma

API: RMA requires a valid connection on both sides
gni: set rate to 52Gb/s

which is observed for RMA on nearest neighbors
Avoid client reconnects

If the client errors and exits, detect if a new instance is trying to
connect to the existing server. Have the server reject the new
connection request.
tests: actually check the crc

Have the server send the crc back.
Properly init the buffer (memset on receiver, random on sender)
Check the crc after a READ on the client
Print the buffer up to 64 bytes
tests: remove dead code
verbs: handle connection failures

Don't silently ignore
tcp: check for RMA operations that have data length + offset exceeding registered memory length
test: rma_verify -- Make sure we do not calculate the CRC on an invalid buffer and let cci_rma() handle the valid buffer.
sock: remove a faulty if condition (incorrect copy&paste).
Enable the detection of the MTU size on MacOS.
sock: code cleanup.
sock: code cleanup.
sock: fix a corner case where the useful payload size was not correctly calculated.
sock: code cleanup
+ correctly display the error message when sendmsg() fails.
sock: In the context of a conn_reject, do an implicit ACK of the initial conn_req to avoid resending the conn_req over and over.
sock: do not take into account RNR in the context of the connection phase.