spacemanager,transfermanagers: Don't rely on SRM db properties

Several service have historically piggybacked on the SRM db
settings. Nowadays each service has its own DB properties, however
spacemanager and transfermanagers defines it's properties in
terms of the SRM properties, thus causing an unwanted coupling.

We still want backwards compatibility and thus let spacemanager
and transfermanagers default to the deprecated (legacy) srm
properties, however the new properties should be decoupled. This
structure matches what is already done in pinmanager.

At the same time, both spacemanager and transfermanagers did
not actually respect it's own properties: That's because they
used the JDBC URL defined for the SRM and these didn't make
use of properties like spacemanager.db.host and spacemanager.db.name.

Target: trunk
Require-notes: yes
Require-book: no
Acked-by: Paul Millar <paul.millar@desy.de>
Patch: http://rb.dcache.org/r/5901/