Better api generation

Things to consider:

• breaking changes (removed imports), so up minor version, because we are still not in 1.0

build.gradle

@@ -251,6 +251,7 @@ task compileListNamesTest(type: RelastTest) {
     grammarName = 'src/test/jastadd/listnames/ListNames'
     useJastAddNames = true
     jastAddList = 'ListyMcListface'
+    listClass = 'java.util.LinkedList'
     packageName = 'listnames.ast'
     moreInputFiles 'src/test/jastadd/Utils.jadd'
 }