Update TODO

- remove analysis and decisions about how to invoke the Fcommand pass code
  back to the background page (it has now been implemented)
Enable strict mode
Update TODO

- remove obsolete point
Update TODO

- representing current thinking
Add debug support for Fcommands

- this is the backend work so that code string generation supports embedding
  the 'debugger' command in the resulting string
- the user has to have devtools open in the page on which the Fcommand is
  being invoked in order for it to work.  If they do, they will be dropped
  into the debugger within the Fcommand wrapper code and can then easily
  single-step into the Fcommand code itself, set other breakpoints, etc.
- currently, setting breakpoints doesn't persist across invocations of the
  same Fcommand (because the Fcommand code is newly injected each time).
Update TODO

- include some common icons since we'll be using them for notifications
  anyway
Remove file

- to be replaced with material design icon
Add basic notification icons

- still need antialiasing
Pass request's cmdline value into Fcommand
Allow debugging Fcommand bg code string
Support debug+help options on all fcommands

- every Fcommand supports --debug (drop into debugger inside Fcommand),
  --bgdebug (drop into debugger inside Fcommand's bg code), --help (to be
  used to popup the Fcommand's help)
- --debug and --bgdebug are handled internally, requiring no support by
  Fcommand authors
- --help is to be implemented
Remove unneeded property check

- the Function() constructor can handle undefined, empty string or null
  as the function body (it creates a no-op function)