Clarified HWM=0 means infinite
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 #533 from mika-fischer/workaround-for-496

Work around for LIBZMQ-496
Added corporate copyrights
On the Tile architecture, use atomic instructions for atomic ptr and counter.

For atomic_counter and atomic_ptr classes, detect the Tile architecture
using #if defined __tile__ matching ARM and Solaris and then use the
Tile atomic instructions. Without this change, the default Mutex
implementation is used, which is slower.
Merge pull request #535 from ken-tilera/master

Optimize atomics implementaiton for the Tile architecture
Merge pull request #534 from hintjens/master

Reverted cleanups of copyrghts
Removed IPC endpoint from test; not portable, and fragile (#80)
Merge pull request #536 from hintjens/master

Fixed test_last_endpoint (#80)
mingw32 fixes
Merge pull request #537 from TTimo/master

mingw32 fixes
Fix MSVC project files.
Windows friendly replacement for gettimeofday
Use Multithreaded DLL Runtime, Debug/Release accordingly - need consistency for the czmq configurations
Merge pull request #538 from TTimo/master

MSVC fixes
restore fixed MSVC 2010 projects, fork new MSVC 2012 projects
InitializeSecurityDescriptor needs Advapi32.lib
Merge pull request #539 from TTimo/master

Adds a needed Windows system library dependency
Added clarification about connect on ROUTER
Merge pull request #540 from hintjens/master

Small clarification about connect and ROUTER