Updated man page
Removed experimental zservice class
Merge pull request #397 from hintjens/master

Removed zservice class
Fixed #398
Deprecated zmsg_push by zmsg_prepend

- method was unsafe, taking ownership of the frame (and destroying it)
  without nullfying the reference.
- deprecated zmsg_push (and also zmsg_wrap which has same issue)
- added new zmsg_prepend () using safe API style

Cause of this change was 2-3 hours lost in zproto tracking down obscure
bug caused by use of zframe_push(). Once is enough. :)
add zcert_save_secret
Merge pull request #400 from genjix/master

add zcert_save_secret
added zcert_save_secret() to documentation.
Merge pull request #399 from hintjens/master

Fixed #398
Merge pull request #401 from evoskuil/master

VS 2013 (v120) solution and projects.