spacemanager: Make database connection pool configurable

Moves BoneCP instantiation into Spring and exposes connection pool parameters
in configuration files.

New configuration properties:

spacemanager.db.connections.partition-count=3
spacemanager.db.connections.max-per-partition=10
spacemanager.db.connections.min-per-partition=1

Target: trunk
Require-notes: yes
Require-book: yes
Acked-by: Paul Millar <paul.millar@desy.de>
Acked-by: Dmitry Litvintsev <litvinse@fnal.gov>
Patch: http://rb.dcache.org/r/6375/