logging: Add trace level logging

Most of the logging is only useful during ioprocess development but not
in release. This makes it so that trace logging is only enabled upon
request.

Bug-Url: http://bugzilla.redhat.com/1114908
Change-Id: Ic1355d1f91831aab114440a3ffa0e0086bb1eead
Signed-off-by: Saggi Mizrahi <ficoos@gmail.com>