* support todo.txt / done.txt
* dynamic toolbar
  * show buttons based on which pane is focused
* toolbar actions: add / remove tasks
  * use global shortcut key event handler rather than taskview key event handler
    * maybe not -- the actions should only be available when taskview is focused, toolbar is supposed to change dynamically
* mark selected task(s) as complete with keyboard (F12 to toggle, figure out if a checkbox is also worth trying)
* more toolbar actions (activatable via hotkeys) that apply to selection: add remove tags / lists with a popover menu / possibly typeahead find
* context menus to do all the above
* custom filters with filter language (implement task objects)
* custom sorting
* grouping
* fast data entry (possibly with autocomplete tags and lists)
  * this may require moving away from the simple text box we use for entry right now
  * this is gonna look awesome, we will overlay a widget that will display +tags and @cats and other metadata with nice boxes
* automatic creation date addition
* undo capability


# Features completed

* search filter box
* exit app toolbar button and key combo
* multi-window: allow new window to be created with key combo and toolbar button
* multi-window: open a file to create an entirely new window
* configure where todo.txt / done.txt are saved
