Merge branch '30-implement-state-copy-in-ast' into 'dev'

eraser-base/src/main/jastadd/Item.jrag

eraser-base/src/main/jastadd/Printing.jrag

eraser-base/src/main/jastadd/Rules.jrag

eraser-base/src/main/jastadd/Rules.relast

eraser-base/src/main/jastadd/eraser.flex

eraser-base/src/main/jastadd/eraser.parser

eraser-base/src/main/jastadd/shem.relast

.../java/de/tudresden/inf/st/eraser/ControllingItemTest.java

eraser-base/src/test/resources/tests/ppc4/input.eraser

eraser-base/src/test/resources/tests/ppc4/output.eraser

eraser-base/src/test/resources/tests/ppc5/input.eraser

eraser-base/src/test/resources/tests/ppc5/output.eraser

...in/java/de/tudresden/inf/st/eraser/spark/Application.java

...ain/java/de/tudresden/inf/st/eraser/spark/SimpleItem.java

...n/inf/st/eraser/feedbackloop/execute/ExecuteImplTest.java