Inform about moved code and prefer it over copied code
Summary:
Also reduce the memory usage a little bit (before increasing it again).
I use the same CSS class as for the copied code.
Test Plan: Parsed 100 diffs and checked about 10 of them - looks good.
Reviewers: epriestley
Reviewed By: epriestley
CC: aran, Koolvin
Differential Revision: https://secure.phabricator.com/D2339