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/
Merge pull request #166 from lclc/travisGithubPageDoxygen

Travis github page doxygen
Let travis only update documentation if changes in master
travis docu fix
Merge pull request #167 from lclc/travisGithubPageDoxygen

Travis github page doxygen fix