Fixed to make work with ZMQ v3.2
Extending Travis CI build to ZMQ 3.2
Extending Travis CI build to ZMQ 3.2
Disabled zmonitor for libzmq v3.2

- current code assumes libzmq v4.x
- whole class and interface is null now when built on libzmq < v4
Fixed zpoller for ZMQ v2
Added zcert_meta_keys method

This gives the caller a list of all the keys in the metadata.
Updated year
Fixed zauth selftest

- was sometimes failing particularly on Travis CI
- had some grunky code due to ZeroMQ's weakness in changing security on
  existing sockets
- now just recreates sockets every time, which is more robust and works
  as normal applications would work
Added pack/unpack methods

- to support FILEMQ protocol and others using same cheap/nasty codecs
- packs hash table into zframe
- designed for protocol headers, max. 255 values, key+value max 255 chars
Minor style changes
Allow project to survive without README
Moved some classes from FileMQ into CZMQ

* zdigest - calculates digest for blocks, using SHA-1
* Creates OpenSSL libcrypto dependency which we detect at configure time
* If libcrypto isn't available, zdigest is stubbed out
* zdir_patch - calculates patch on directory changes
* zdir - added methods for directory differences and caching
Fixed memory misuse error
Fixed some build errors on new digest code
Was trying to include uuid.h when not installed
Merge pull request #296 from hintjens/master

Fixed to make work with ZMQ v3.2