Check that any partners exist prior to trying to find out their synapses.
Addresses the error message seen when using AND in the connectivity widget
and no common partners exist.
Make argument be direct rather than a keyword argument.
Added "Measure" button to Selection Table, which opens the Skeleton Measurements Table
which contains cable length, smooth cable length, and info on nodes and synapses
for every selected skeleton in the Selection Table.
Merge branch 'master' of github.com:acardona/CATMAID