Investigate resizing of selections

[dshorthouse]

While the typical use-case is probably to select a few words here and there, it's entirely possible that someone may want to use this to select rather large blocks of text. This means that the iteration of click or double-click to add/select and then right-/control-click to remove is unwieldy. One solution to this is to add resize handles on left-most and right-most extremities of a selection to permit drag to resize.

[mjy]

Completely agree for large texts. For small labels I think we might be OK though. Wondering how we can get user feedback to test and find a sweetspot.

To rephrase we're saying:

When I select a huge block of text, 
   and I am off by 2 characters
        then I have to re-highlight the whole huge block
           and it might be faster to simply drag handles to adjust the highlight at the start and end

Thought:

What if rather than handles on the highlight (perhaps lots of DOM work etc.) we place +/- buttons in to places besides the copied version of the text- this let's user click one or two times on either side to expand selection?

[dshorthouse]

A click to expand/contract would work too but the extra bits of UI element might obscure the content below.