Merge pull request #161 from hintjens/master

First cut of zcurve, plus some cosmetic fixes
va_{start,end} needs to be called for each vsnprintf
MSVC vsnprintf differs from POSIX

it returns -1 on truncation
if it returns sizeof(buffer), the buffer is not NUL terminated
fix vsnprintf usage
Merge pull request #166 from pijyoi/fix-vsnprintf

Fix vsnprintf for zmsg.c and zstr.c
Removing syslog.h from czmq_prelude.h
Merge pull request #168 from jlopezr/master

Issue #167
Fix zcurve.c so it builds on Windows
 * Don't include platform.h when building using Visual Studio
 * umask doesn't work the way it was used here, so just don't call
   it on Windows
 * Make sure to cast void * to the type you're assigning it to on Windows
Changes nothing, just rearranges the sections as visual studio likes
Add RelWithDebInfo configuration

 * This builds the Release DLL and also Debug info pdb files
 * Debug info is no longer built for the ReleaseDLL configuration
Change so we only don't include platform.h when using visual studio, but do otherwise
Make build directory for Win32 RelWitDebInfo $(PlatformName)\$(ConfigurationName)
Add zcurve.[ch] to the czmq project
Merge pull request #169 from vortechs2000/more_windows_fixes

More windows fixes
Man pages rebuilt automatically
Second draft of zcurve module
- sending/receiving frames over DEALER-ROUTER, in selftest
- new module, zblob, for size-specified binary strings
zcurve works with variable messages
- beginning to support metadata
- removed zblob class again, it's not needed
Added -lpthread to link statement
Fixed lots of small faults in recently added code
- variable names like 'i' and 'strSomethingBogus'
- memory leaks in selftests
- general indentation and layout
Removed latest zero_copy additions in zframe and zsocket
- the code was complex and I'm skeptical that it is necessary
- it was leaking memory in selftests and I did not find the cause
- if we do *need* zerocopy all over the place I'd like to find a better API