src/browsewrap.c: type accuracy and cleanup.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
(GetSMBShare): type accuracy and port to GIOChannel.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
(GetSMBMachines): type accuracy and port to GIOChannel.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>