TeamCityDatePlugin: date and branch names for build numbers

Development notes

To build, test, and package the plugin, run mvn package from the root directory.

To deploy the plugin, copy date-plugin.zip into the TeamCity plugin directory and restart the server. If you've built locally, get the zip file from target/date-plugin.zip

Credits

Heavily inspired from the following sources

• Date Build Number by Yegor Yarko
• ParaMetrics by sferencik