rvalue ref / C-string upper

[yakra]

in mark_chopped_route_segments and mark_connected_route_segments rvalue refs don't seems to help all that much (elsewhere, at least)

• [x] taskscale lct* (2<->3; 2A<->3A specifically), include 3A's diffs if rvalue refs actually help	BT	lab1	lab1.5	lab2	lab3
  !	no	-0.0052	no	-0.1268

• [x] Where else is std::string upper(std::string str) still used?
  • ~Comment out the definition and see what breaks to find it fast. :)~
  • Nah, just search. Very few occurrences.
  • Only Route ctor.

  • [x] Did && help?	BT	lab1	lab1.5	lab2	lab3
    !	no	no	no	-0.0152

  • [x] Candidate to change over? Eh. Only 1.8s on BiggaTomato. But why not!
• [x] then try replacing entirely: set up the std::string, then upper its .data() in situ