Merge pull request #35 from RAOF/send_add_event

Send “add” uevent when adding a device
Allow passing “NULL” as the device node in umockdev_testbed_load_ioctl

This requires storing the name of the device node umockdev-record is recording
from. This now happens in a "@DEV /dev/path" line at the top of the *.ioctl
file.
bump version to 0.6, new features/behaviour
add issue #33 ref to NEWS
release 0.6