Enable OSX builds for Travis CI. Created bootstrapping for thrird party dependencies.
No need to sudo for brew. Also minor fix in running install script.
brew fixes and removed zmq.
Installing openssl with brew.
Merge pull request #162 from murrekatt/develop

Travis configuration to build on OSX too
Let Travis update online documentation (Doxygen) at every upstream change
https://open-transactions.github.io/Documentation/