* use <copyPaste.canCopyProperty> event to copy category value when copying group
* add camunda-bpmn-moddle for integration tests
BREAKING CHANGES
* CopyPaste: remove <property.clone>, add <moddleCopy.canCopyProperties>, <moddleCopy.canCopyProperty>, <moddleCopy.canSetCopiedProperty>
* BpmnRules: removed <elements.paste> rule in favor of <elements.create> rule
* BpmnRules: removed <element.paste> rule
* ElementFactory: use <attrs.di> property instead of <attrs.colors> for fill and stroke when creating element through ElementFactory#createBpmnElement
This commit adds the ability to model participants from the palette.
* Empty diagrams can be used as a start for participant _AND_ process diagram
* Process diagrams can be converted to collaboration diagrams by dropping
a participant onto them
Closes#128