console: deeper tasks exec history in csv, and several minor enhancements
executor code simplification and optimization

* avoid duplicate code blocks
* avoid creating empty TaskRequest and QProcess for nothing
fixed a (rather rare) multithread bug crash

was crashing with "double free" in ~QDateTime

this commit also enables multiple trigger specifications per "trigger"
node in configuration, such as:
(trigger(cron 0 * * * * *)(cron 30 * * * * *)(notice foo))
console: replacing T with space in timestamps

less compliant to ISO8601 but more readable and timestamps are splited
across several lines
console now provide >=warning and >=info log views
console: adding task info url
console: fixing some captions