Allow only-active when no query is specified.

Previously, the --only-active option only worked when
specified in combination with a query.

This commit adds support for searching for all active nodes
with an empty query.
Add deactivate option

This commit adds an option:deactivate that can be used
to deactive all nodes that were returned as the search
results.
Merge pull request #19 from bodepd/add_deactivation_opt

Add deactivation opt