added layout related base implementations

org.fortiss.tooling.base/trunk/META-INF/MANIFEST.MF

org.fortiss.tooling.base/trunk/model/base.ecore

org.fortiss.tooling.base/trunk/plugin.xml

...unk/src/org/fortiss/tooling/base/compose/DropContext.java

...org/fortiss/tooling/base/editor/TreeViewerEditorBase.java

.../fortiss/tooling/base/editpart/ConnectorEditPartBase.java

...ooling/base/editpart/GraphicalConnectionEditPartBase.java

.../fortiss/tooling/base/editpart/GraphicalEditPartBase.java

...tooling/base/editpart/LayoutedConnectionEditPartBase.java

...g/fortiss/tooling/base/editpart/LayoutedEditPartBase.java

...c/org/fortiss/tooling/base/editpart/NodeEditPartBase.java

...fortiss/tooling/base/editpart/PositionedEditPartBase.java

...c/org/fortiss/tooling/base/editpart/RootEditPartBase.java

...ng/base/editpart/anchor/InsetChopBoxConnectionAnchor.java

...k/src/org/fortiss/tooling/base/layout/IPointLayouter.java

...iss/tooling/base/layout/constants/LayoutKeyConstants.java

...ing/base/layout/constants/RecommendedLayoutConstants.java

...fortiss/tooling/base/layout/util/EditPartLayoutUtils.java

...org/fortiss/tooling/base/layout/util/LayoutDataUtils.java

...rg/fortiss/tooling/base/layout/util/OrientationUtils.java