Finished authentication support in CZMQ (first draft)

* Does not yet support multiple domains
* Adds zcertstore class for managing certificate stores
Show ALLOWED/DENIED outcomes if verbose is set
Simplified white/blacklisting

* Configure via API rather than external file
Added CURVE_ALLOW_ANY to permit anonymous clients over CURVE
Added security pattern examples

* Also fixed makefile for distribution
* Specific LICENSE for security examples -- MIT/X11
Fixed reporting in security examples
Merge pull request #231 from hintjens/master

Finishing up first round of security classes