74.multi task control

Addresses #74. More functionality for several hundred lines less code :-)

Control commands (trigger, reset, kill etc.) can now operate on multiple tasks or (members of) families matched by regular expression. Similarly gcylc right-click menus for family nodes or names.

To test I suggest putting a test suite with families in the held state, and then control the hell out of it by cli and gui. 

Passes the test battery with two suites modified to use 'at' job submission, pending fix for #415.