Use same technique as rest of ZMQ libraries to build in MSVC
Fix casts for buildnig in MSVC
Merge pull request #243 from twhittock/msvc-build

Msvc build shakeup
Update zre_msg.xml and regenerate message file.

Note this removes void * casts which were added in 897c074 - however I just built this in osx and it works fine
Merge pull request #244 from twhittock/msg-regen

Update zre_msg.xml and regenerate message file.
Add project generation scripts for visual studio.

The scripts are taken from CZMQ, only guids are changed
Update cmake build script.

Taken from the CZMQ cmake build script, with the CZMQ dependency retained.
Note that this fixes the ZYRE_EXPORTS symbol, by using project.name macro
Regenerate build files based on latest templates
Merge pull request #245 from twhittock/master

Generate MSVC project files using gsl, instead of using hand-written ones.
Tracking changes to zproto class properties
Problem: lack visibility of current set of peers

Solution: add zyre_peers method which returns a zhash of the current
peers. The caller can use the hash keys (peer identities). There is
no other useful information in the hash table.

Fixes #246
Merge pull request #247 from hintjens/master

Added zyre_peers method
platform header missing from msvc directory, due to gitignore rule