ui: workflow graphs background set to transparent instead of white
ui: consistency of trigger-to-workflow-step edge styles accross diagrams
config: removed a false error log within event subscriptions

Used to complains (param) in any event subscription and about
(cron) and (notice) subnodes in (ontrigger) declaration since they
are not valid action names.
config: fixed "ignoring trigger in workflow task" warning log

The warning was not issue in the right case at all (false positives
and false negatives).
ui: changed log icon
ui: fixed-width icons in button-like spans and tables first columns