Passenger_flag now beeing removed from affected vehicle part
Fix advanced menu up key in category sorting corner case

Fixes issues #8014 and #7700
Made the advanced inventory selector behave as expected when going up
into a page that happens to end in a category header in sort by category
mode.
Fixes issue #7695
Made techniques have a boolean field "dummy" to determine they should always be skipped in the technique choice. The old method for determining this kind of skip made no sense.
Changed block techniques descriptions.
Changed blocking techniques' descriptions to better reflect their action as requested by KA101.
Fixed UTF-8 issue/derp
Fix rollerblade dodging

Not sure how I missed this in mergetesting.
Adds textbook_traps spawns

For some reason this never got a spawn.  Now you can find it in the
camping, textbooks, pawn, and mil_surplus groups.

Thanks for the report, vache.
Merge remote-tracking branches 'dda/pr/8031', 'dda/pr/8046', 'dda/pr/8049', 'dda/pr/8051' and 'dda/pr/8053' into dda-master

* dda/pr/8031:
  Passenger_flag now beeing removed from affected vehicle part

* dda/pr/8046:
  Fix advanced menu up key in category sorting corner case

* dda/pr/8049:
  Fixed UTF-8 issue/derp
  Changed block techniques descriptions. Changed blocking techniques' descriptions to better reflect their action as requested by KA101.
  Fixes issue #7695 Made techniques have a boolean field "dummy" to determine they should always be skipped in the technique choice. The old method for determining this kind of skip made no sense.

* dda/pr/8051:
  Fix rollerblade dodging

* dda/pr/8053:
  Adds textbook_traps spawns