RFE: taskopen -h
-h as in help.
As it stands, if taskopen is run with no arguments, the program gives helpul feedback;

djp@tigger:~$ taskopen.pl
Usage: /home/djp/bin/taskopen.pl <id|filter> [\label]

Current configuration:
BROWSER   = xdg-open
TASKBIN   = /usr/bin/task
FOLDER    = ~/tasknotes/
EXT       = .txt
EDITOR    = vim
NOTEMSG   = Notes
NOTES_CMD = ~/tasknotes/UUID.txt

but this request is to change that behavior.
Instead, if run with no arguments, status:pending should be presumed, and every eligible annotation should be displayed, as though something like "taskopen all" were issued, 

The helpful output that is currently triggered by "taskopen" with no arguments, should instead be displayed only when the "-h" flag is used.  
