[connman] change all connman_info to DBG

connman_info does not have file names in it's output, so it would not
be included in the block out by doing -d '*:!src/rtnl.c'

This effectively makes the output more manageable and readable when
debugging.
This included stat and newlink info clogging the output.
Merge pull request #91 from lpotter/debugs

[connman] change all connman_info to DBG