Working on actions using expressions.

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

...de/tudresden/inf/st/eraser/parser/EraserParserHelper.java

...ain/java/de/tudresden/inf/st/eraser/util/ParserUtils.java

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

...e/src/test/java/de/tudresden/inf/st/eraser/RulesTest.java