Mark occurrences

[pq]

(from user-submitted feedback).

[danrubel]

Changed the title to: "Mark occurrences".

[danrubel]

Issue #2632 has been merged into this issue.

[stevemessick]

Set owner to @stevemessick.
Added this to the M1 milestone.

[alan-knight]

I'm seeing this in the latest editor build and finding it a bit confusing. Especially to begin with, where I saw something that looked like selected text that couldn't be un-selected. I think partly it was because it persisted well after I had typed the thing it was matching, so I didn't realize it was related to that, it just seemed to be selected for no obvious reason. Once I noticed it happening as I was typing it became clearer. But maybe it should go away sooner - not sure how to define that, though.

[stevemessick]

Added Fixed label.