Minor edits to add to conflictResolution tool

[mgorra]

--Add a margin between the end of lines and the edge of their document.
--Change the popup location so they don't block apply buttons etc (this might conflict with standardization).
--Should just rejecting one side of a conflict count as handling it? (It currently does).
--Have the caret for the middle document point in between the two edges of the conflict, rather than at the line above/below it. This could be tricky, since the caret's library bases position on line.