update comment to match actual output
break sending newsletter on failure if in debug mode

for easier debugging
add fullPage cache for mail component

move Mail HtmlParser into renderer so we can cache it in fullPage cache
add benchmark checkpoints when for mail component, to allow profiling newsletter sending performance
add cache for mail redirect rows, improves newseltter sending performance
if speed is set to fast don't sleep at all
disable ModelObserver while seinding newsletter

We don't need it and it slows just down everything
add benchmark output while sending newsletter with debug parameter
only change status if not sending already
move Newsletter_Model::send into controller

it can't be overridden anymore

current implementation was problematic as it picked always only the first model
end newsletter sending process not with time limit but with memory limit
start multiple processes for sending newsletter mail (currently hardcorded to 5)
move newsletter row send method into cli controller

gives better fexibility and it's called from there only anyway
also move sendMail method into cli so we can create better debug output
add parameter to define maximum number of started processes
don't start all processes at the same time

this will give the first one time to warm up view caches
rename method to make clear what it returns
make sure we don't send a mail twice to a user from two processes
remove check for other process

- it doesn't really harm if two processes would send
- it is ensured that only one newsletter start process runs
support command with spaces