Log Message:
* Convert to USE_TOOLS+=itools instead of including nbitools/buildlink3.mk.

* Fully convert to the pkginstall framework by using it to manage
  directories required at install time.

* Rewrite the canna rc.d script to ensure that all needed directories
  are present before the daemon is started.

* Miscellaneous touch ups to the DESCR and MESSAGE files.

* Remove the need to explicitly set PREFIX.  These packages now install
  into ${LOCALBASE} and use symlinks and file copies to put the files
  into the ${IMDICTDIR}.

Bump the PKGREVISIONs for the canna* packages.