Automatically calculate text report table column size

This is in preparation for the longer columns for onsite hours
reporting.
Fix printing of large text in text reports
Report onsite hours

Onsite hours are picked up from PHPReport tasks and included in reports
now.
Fetch tasks in parallel

This speeds up the generation of aggregate reports greatly.
Abstract parallel URL fetcher into a function
Improve the help output slightly
Be a little smarter about linking to detailed reports

The Twiki uploader still isn't very smart about replacing the short
description with the link, but at least it now handles short names that
are substrings of others in some cases now.
Don't print total hours again in detailed report

This looks really odd in the Twiki output.
Replace --twiki with --formatter

This makes way for a --twiki mode which will soon replace --upload.
Change --upload to --twiki mode

TWiki mode has slightly different behavior than the default mode. In
addition to using the TWiki formatter, when generating aggregate
reports, detailed reports are also generated and uploaded.

This needs to be optimized by doing uploads in parallel.