closes #562

Please note:
Docs are outdated
Env manager, Hystrix, Jolokia, metrics still missing

closes #465

closes #627

In order to make the starters compliant to the spring boot naming rules
I added a codecentric-* prefix to the server and the client starters.
All samples are now using our starters and the docs were alignes with
these changes. In order to not suprise existing users I've added a
relocation to our old module

I removed the unecessary plugins from the build and reworked it to use
the ci friendly way of setting the version for releases (see
https://maven.apache.org/maven-ci-friendly.html).

This removes the spring-boot-starter-parent from the build, and
duplicates the necessary plugin configuration in he Spring Boot Admin'
parent instead. This way our BOM doesn't include version for
dependencies managed by boot's BOM

Reduce bundlesize by picking parts of fontawesome and d3
Add mixings for subscribing components

To allow hot reloading for templates and resources add according
properties.
Add instructions in the README.md on how to develop the ui

The info should be updated when the registration has changed. In order
to prevent a stale instance info, the sba client includes a "startup"
timestamp in the metadata as default. So when the instance is restarted
the registration changes and the info is updated, even when the instance
isn't considered as down in between.

To prevent this when using a discovery client you need to add a value
to the metadata which changes with every restart.
(e.g. `random=${random.value}`)

fixes #556