Add a TODO file for the locking implementation.
Add a TODO file for the locking implementation.

* notes/locking/TODO.txt: New file.

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