Adding new functions to get protocol's default options

Adding new functions to get protocol's default options

Adding new functions to return the default values to protocol options
and protocol options labels.
Also defining __id and __exists as object to fix execution's failure.

Signed-off-by: Ragner Magalhaes <ragner.magalhaes@indt.org.br>
Acked-by: Bruno Abinader <bruno.abinader@indt.org.br>
Acked-by: Ricardo Guimaraes <ricardo.guimaraes@indt.org.br>

git-svn-id: https://garage.maemo.org/svn/carman/branches/carman-0.7-beta2/python-purple@1425 596f6dd7-e928-0410-a184-9e12fd12cf7e