Improve Project Structure

At the moment there are the following projects:
Baselet is the Swing Standalone and Eclipse Plugin project
BaseletGWT is the GWT based Web-Version
BaseletElement is the project containing shared files

The GWT and Swing part work fine with Project References, but the Eclipse 
Plugin handles dependencies differently than Java.
This is not a problem for the ant build, but in Eclipse "Run As -> Eclipse 
Application" only works if dependencies are correctly set up.
Therefore links the sources instead (see also README.txt in Baselet project)

A possible improvement of the structure could be migrating Umlet to Maven.
This could simplify the dependency handling (and unify the build process).

It should be evaluated if the final result will be simpler or more complex 
(especially for newcomers)

Alternatively it could be evaluated if there is a simpler way to setup the 
correct Eclipse Plugin dependencies.

Also splitting the Baselet project into BaseletSwing and BaseletPlugin could be 
useful (to remove the Plugin dependencies from the Swing Project)

Original issue reported on code.google.com by AFDiaX on 10 Aug 2014 at 7:53

achuanle / umlet

Improve Project Structure #189