With this commits the server no longer depends on the client. The
classes for the clients are moved to de.codecentric.boot.admin.client
package.
Since the perspective on applications is totally different from client
and server the model has been split apart.

What means this for users:
1) The client is no longer a transitive dependency for your admin server
you may need to add it explicitly to your dependencies, respectively
jolokia-core in case you're using discovery and want to use the jmx-bean
interface

2)In case you have cutomised parts of the client you need to reflect the
package change.

fixes #332

closes #299

As now with spring boot 1.4 there is a special goal for generating the build-
information, we use it for displaying the version in spring boot admin. The old
info.version property still works but is deprecated. From now on
build.info.version is taken into account.

The 1.4.0 release was a total disaster. Webpack didn't build the css correctly
because of travis using an ancient nodejs version.

The polling in the UI is replaced with server side events. Status changes are
now reported immediately from the admin server to the UI.

I did an accidental release of a 1.3.2, so we need another increment

remove logfileEndpoint
rename logback.xml to logback-spring.xml in samples

fixes #98

Remove unecessary dependencies