(1) Upgrade subversion to version 1.5.0.
(2) Make binding ports to be real ports, which installs only bindings and
depend on subversion.
(3) Rename bindings ports to reflect perl5/python/ruby modules naming scheme.
(4) Re-base subversion-freebsd to `devel/subversion'.
(5) Fix all ports, which depends on subversion bindings.