Running server.sh after cloning and building did not work without
also customizing paths and/or moving files around.
By referring to already existing default locations the out-of-the-box
experience should be a bit smoother.
In order to not affect existing installations and to retain support for
running released versions from http://brouter.de/brouter/revisions.html,
the old default paths are still checked.
By setting BINDADDRESS and delegating to server.sh we can avoid
duplicating most of the code.
This also makes 0d5e1c1 available for local.sh, i.e. being able to
launch local.sh from arbitrary directories too.
