remove unused imports
add unit test which demonstrates issue32

Specifically [] should parse as something that implements RandomAccess,
while () should not.
This fixes issue32

When parsing a list ( … ), we now return a DelegatingList wrapping
the underlying ArrayList. DelegatingList has the property that it
does *not* implement RandomAccessList. From this fact, the Printer
will conclude that it should be printed as a list ( … ) and not a
vector [ … ].
Merge branch 'feature/issue32' into develop

* feature/issue32:
  This fixes issue32
  add unit test which demonstrates issue32
  remove unused imports
set version to 0.4.2 for release
Merge branch 'release/0.4.2' into develop

* release/0.4.2:
  set version to 0.4.2 for release
prepare pom.xml for development by setting version to develop-SNAPSHOT