check uniqueness during serialisation, fix nullpointer issues in rewrite checks, add test for node removal

Add flag `--useJastAddNames` generate names in the form of addX, removeX and setX. If omitted, relast will default to the original naming scheme addToX, removeFromX and setX.

make unresolved subtypes of abstract types abstract, use unresolved interface. rename resolver methods (for MQuAT compatibility)

add resolveAll and treeResolveAll functionality to ensure all references are resolved (important for bidirectional references)

add a parameter --grammarName=<name> to set the name of the generated files (without extension). Otherwise it is 'Grammar'

- "addToX" -> "addX"
- "removeFromX" -> "removeX"
- "x()" -> "getXs" and "getXList"