AM_CONFIG_HEADER -> AC_CONFIG_HEADERS

AM_CONFIG_HEADER raises an 'obsolete error' with automake 1.13.
Merge pull request #75 from hintjens/master

Backported c436c8
LIBZMQ-497 there could be unsent bytes in encoder

When we send a large message, the message can be splitted into two chunks.
One is in the encoder buffer and the other is the zero-copy pointer.
The session could get the term before the last chunk is sent.
Merge pull request #76 from hintjens/master

Backported fix for LIBZMQ-497
Backport of test_connect_delay refactor
Merge pull request #77 from ianbarber/master

Backport of test_connect_delay refactor from master
Patch from Rob Gagnon, backport of test fix from master. Resolves LIBZMQ-462
Merge pull request #78 from ianbarber/master

Backport of test_last_endpoint shutdown fix, resolves LIBZMQ-462
Work around for LIBZMQ-496

The problem is that other threads might still be in mailbox::send() when
it is destroyed. So as a workaround, we just acquire the mutex in the
destructor. Therefore the running send will finish before the mailbox is
destroyed.

See also the fix for LIBZMQ-281 in zeromq2-x.

Signed-off-by: Mika Fischer <mika.fischer@zoopnet.de>
Merge pull request #79 from mika-fischer/workaround-for-496

Work around for LIBZMQ-496
[#LIBZMQ-446] Silence error on setting PGM_TOS due to some platforms raising an error at runtime.  Noted are RHEL 4.
Merge pull request #81 from steve-o/libzmq-446

[#LIBZMQ-446] Silence error on setting PGM_TOS on REL 4.
Merge remote-tracking branch 'upstream/master'