Handle return differences in sterror_r on freebsd

strerror_r returns an int and sets tempstr to the error string
on freebsd. On linux, the actual error string is returned.

Signed-off-by: Viji Ganapathi <vganapathi@panasas.com>
cmake changes to link dbus and set cmake policy

The cmake policy specified is used to give CMAKE_MODULE_PATH
preference over build environment paths during compilation/linking

Signed-off-by: Viji Ganapathi <vganapathi@panasas.com>