Improve separation of concerns in ansible roles

[minnsoe]

The provisioning playbook uses roles defined to tackle a particular area of system provisioning. For example, the development role sets up tools and utilities for programming environments. However, the development role actually provisions multiple programming environments. Changes to a browser focused development environment should not really affect one that uses the JVM for instance.

The roles should be as granular as possible, giving only one reason to change. The playbook itself should tag the general category, e.g. development, and trigger the role if it matches.