control: Don't cache non-group properties

The code was previously adding every single D-Bus
path/interface/property of a service when Manager::addObjects() was
being used to cache D-Bus property values.  This was resulting in a lot
of extra items in the cache that fan control would never use.

To fix this, create a single static set of all of the D-Bus paths from
all of the Group objects, which would be the master list of all the
D-Bus paths fan control would ever care about.  Then, only add a
path/interface/property to the cache if that path is in that set.

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I787c9c36b88d003fe9fe7ac1d517fbb5aa510e4e
4 files changed