It should be possible to open a CAS file from a non Cas Editor project

It should be possible to open a CAS files which are inside an eclipse java project (and not an eclipse CAS Editor project) with the CAS Editor.

After spending more time on the issue the plan how to implement it changed again.
The previous idea of having an additional plugin for this functionality is dropped and the change is directly
integrated into the Cas Editor plugin.

There are two changes which must be performed for this issue:

1. The Document Provider is extended with a custom logic to open a CAS file from a non Cas Editor Project.
Its assumed that the type system is placed in a certain location, if it cannot find in this location the
user if prompted by a dialog to provide a valid type system for the CAS.
This mechanism should be improved in the future to play nicely together with all other plugins wich also need
access to a type system, like the description editors.

2.
The UI to configure the annotation styles must be moved to the editor and away from the Cas Editor Project
handling code. To accomplish this the Document Provider should be responsible for accessing/modifying
the styling information. A new view is added to the editor which can display the styling information and
gives access to the annotation property dialog to modify the styling.
The styling information is shared between all editors type system wide, if the style is changed in one editor
its changed in all other editors which display a CAS with the same type system.

The goal of this issue is to create an initial solution which can then be refined
by input from users and other uima developers.