#31 UML diagram, reduce use of java class loading.

[Jürgen Kellerer]

The current UML class diagram uses several steps of class loading to fetch the metadata that it requires.

Class loading should however be reduced (e.h. by using a central cache map) as it has problems when classes are spread over multiple modules. In particular while the initial class loading operation can work with module prefixes to find classes that are included inside the diagram, the subsequent class loading steps will fail if more than one module is involved as only the last module prefix is reused.

This a diagram where ClassA references ClassB and both classes are in different modules is currently not possible to be created as the call to

%{include|uml-class-diagram=[moduleA]:ClassA,[moduleB]:ClassB}

fails to render the SVG images.