Allow user to select a chunk of text from page being bookmarked to serve as description

[dajbelshaw]

From the etherpad:

I like bookmark tools that allow me to select a chunk of text in the source page to populate the description in the form. I like tio re-write, but w/o that I end up flipping back and forth to compose a description.

Cool. Atul, is that an easy-ish thing to do?

It's super easy to use the current text selection (if one exists) to pre-populate upon activation of the bookmarklet; harder to present the user w/ a UI upon activation asking them to select text, but doable. alternatively, we could also search the page for a meta description tag and use that to pre-populate: http://en.wikipedia.org/wiki/Meta_element#The_description_attribute

https://etherpad.mozilla.org/weblitmapper-feedback