initial commit of spray/graphiti project for composite diagrams

.../CompositediagramLayoutCompositeComponentFeatureBase.java

.../features/CompositediagramMoveAssemblyContextFeature.java

...tures/CompositediagramMoveAssemblyContextFeatureBase.java

...atures/CompositediagramMoveCompositeComponentFeature.java

...es/CompositediagramMoveCompositeComponentFeatureBase.java

...mpositediagram/features/CompositediagramPasteFeature.java

...itediagram/features/CompositediagramPasteFeatureBase.java

...eatures/CompositediagramResizeAssemblyContextFeature.java

...res/CompositediagramResizeAssemblyContextFeatureBase.java

...ures/CompositediagramResizeCompositeComponentFeature.java

.../CompositediagramResizeCompositeComponentFeatureBase.java

...eatures/CompositediagramUpdateAssemblyContextFeature.java

...res/CompositediagramUpdateAssemblyContextFeatureBase.java

...ures/CompositediagramUpdateCompositeComponentFeature.java

.../CompositediagramUpdateCompositeComponentFeatureBase.java

...compositediagram/internal/ExecutableExtensionFactory.java

...tory/compositediagram/property/AssemblyContextFilter.java

.../compositediagram/property/AssemblyContextFilterBase.java

...y/compositediagram/property/AssemblyContextIdSection.java

...mpositediagram/property/AssemblyContextIdSectionBase.java