Fixed some of the problems mentioned in issue #27: Templates can be link options

* parser-toolkit 6b4e2f1...d3974ac (1):

    commit d3974ace72ab7bddd7ae0969b212cf9d1afbadec

        Added prepend and append methods to RtData and fixed NPE in older prepend method.

* sweble-wikitext 121d2af...d5855e7 (2):

    commit d5855e7f957b9d0af8e6ad7469b773734b786fd6

        Fixed some of the problems mentioned in issue #27: Templates can be link options

    commit 8d1a7af7c5e4acbea901b8d1a175c9239400e12a

        Added prependRtd und appendRtd methods to Roundtrip.rats