- Modified ChunkString._VALID: added $ to end. - ChunkString.xform() will now leave the chunkstring unmodified if   _verify reports an error. - Simplified RegexpChunkRule.__init__ - Removed unnecessary import
- Modified ChunkString._VALID: added $ to end.
- ChunkString.xform() will now leave the chunkstring unmodified if
  _verify reports an error.
- Simplified RegexpChunkRule.__init__
- Removed unnecessary import


svn/trunk@5395

nltk/nltk,nltk/nltk,nltk/nltk