Add design discussion notes by Stephen Butler.
Add design discussion notes by Stephen Butler.

* notes/tree-conflicts/detection.txt:
  Expand on use cases 4 to 6 by describing the current plan for
  finding in the repository history the information needed to
  detect tree conflicts during merge.
  Move "true rename" discussion to the end of the file.
  Also improve wording of existing text a bit.

Patch by: Stephen Butler <sbutler@elego.de>

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion