Update NEWS for 1.6.2 release

Print a nice warning and error out if attempting to enable OMPI progress threads without also enabling ORTE progress threads, which in turn requires libevent thread support.

May not be required long term, but as Chris points out, you need all three right now.

Sync NEWS with v1.6 branch

Allow developers to enable OMPI progress threads for debugging purposes. Warn and error out if ORTE progress threads are enabled, but they forgot to enable the libevent thread support.

Ensure we assign "err" properly when invoking MCA_PML_CALLs. Although
technically this is a necessary thing to do, it wasn't a tragedy that
we didn't have it because err was initialize to 0 in the beginning of
the functions where this problem occurred. Also, OMPI will likely
abort if one of the MCA_PML_CALLs actually incurs an error (or, even
if it doesn't, MPI doesn't define the behavior anyway ;-) ).

But looking forward to an FT-aware world, fixing this issue is a Good
Thing. Many thanks to Hristo Iliev for pointing out the issue.

Add a filem test program and set ignores

Gah -- meant to make these changes before committing to SVN. :-\

Hide some struct declarations in the .c file to emphasize that they
are not part of the public opal_hotel interface.

Add new "opal_hotel" class. Abstractly speaking, this class does the
following:

* Provides a fixed number of resource slots (i.e., "hotel rooms").
* Allows one thing to occupy a resource slot at a time (i.e., each
hotel room can have an occupant check in to that room).
* Resource slots can be vacated at any time (i.e., occupants can
voluntarily check out of their hotel room).
* Resource slots can be occupied for a specific maximum amount of
time. If that time expires, the occupant is forcibly evicted and
the upper layer is notified via (libevent) callback (i.e., the maid
will kick an occupant of out of their room when their reservation
is over).

This class can be to be used for things like retransmission schemes
for unreliable transports. For example, a message sent on an
unreliable transport can be checked in to a hotel room. If an ACK for
that message is received, the message can be checked out. But if the
ACK is never received, the message will eventually be evicted from its
room and the upper layer will be notified that the message failed to
check out in time (i.e., that an ACK for that message was not received
in time).

Code using this class is currently being developed off-trunk, but will
be coming to SVN soon.

Fix UWL listing

function mca_btl_openib_endpoint_post_send can return 3 statuses:
- OMPI_SUCCESS
- OMPI_ERROR
- OMPI_ERR_RESOURCE_BUSY

If an "OMPI_ERR_OUT_OF_RESOURCE" occurs, the request is added to the pending list, and will be handled later. An error message
should not be printed to the user in this case. This is not an error, but rather a notification of a possible valid condition.
Only in the case of "OMPI_ERROR" should it be printed to the user.