Forks ddl sequencer so that it can be patched

* Temporary forking of the ddl sequencer where inclusion in the source
  allows bugs to be triaged and fixed.

* Modeshape project cloned into target directory then the sequencer
  directories copied to the project's forked directory.
Adds DdlNodeVisitor converting modeshape back into text

* DdlNodeVisitor
 * Based on Teiid's DdlStringVisitor
 * ... ... ...