Force an integer for the return of Shell::columns(). In cases such as a cron job for which there's actually not a terminal, this call will return an empty string, which in turn causes $size in Bar::display() to be negative, which in turn causes a php warning because the second parameter to str_repeat() must be >= 0.
Make sure we have a size >= 0 so that we never get a negative number as the second parameter sent to str_repeat(), which results in a php warning.
Merge pull request #42 from dllh/master

Force an integer for the return of Shell::columns(). In cases such as a ...