rename runRequestedTasks() to run()
rename _runController() to _runScheduledTasks()
fork once foreach controller, not foreach task

This reduce the number of forks, and avoid cluttering parent process
memory with the code needed for HTTP ocmmunication.
rename runTask() to runTaskIfScheduled()
better log messages
initial import
insert stylesheet reference in message

TODO: compute stylesheet path automatically
drop --html option
make html option as deprecated
local option is deprecated also
drop HTML format output support

This is now externalized as an XSLT transformation.
use an explicit parameter for message filtering
no need for response
handle message in task
pass filename hint for each message
drop function for better readability
create a single recipient for all tasks
no need for task-specific code anymore
no need for a specific class
no need for a specific class