For triggers:
=============

Add to Vectors
--------------
- triggering will be a property of vectors
- add a grouped option section to the Edit Vector dialog called "Update
Options"
- have two mutually exclusive options in this section
    - Read from file continuously
    - Only update when triggered

Add to Events
-------------
- in the Event Monitor dialog, in addition to Kst Debug Log and
  E-Mail Notification, add a section called "Vector Triggering"
- in the Vector Triggering section, have a checkbox called "Trigger:"
- to the right of the check box, have a drop-down list of triggerable
vectors
  (i.e. vectors for which "only update when triggered" have been checked).