This submission add responses for the Engineer for the Payload gamemode to scripts/talker/engineer. Engineer DOESN'T HAVE ANY SPECIFIC RESPONSE FOR THAT GAMEMODE, unlike all the other classes except Pyro.

Some responses related to pushing the payload were added for the Engineer in the Scream Fortress 2013 update for Helltower (plr_hightower_event). I decided to reuse those responses.

NOTE FOR THE TF2 TEAM: Since the responses are "auto-generated" (as the notes for Cart responses say), I fear that my submission, if added, could be deleted automatically. TF2 team, please check it this won't happen. Thanks!

Some responses use "speak" instead of "scene" because:
1. there is not specific .vcd file for it. For example, in the case of "engineer_cartgoingforwardoffense01", I can't just use conga.vcd
because it calls for a soundscript that uses a rndwave. I had to create new soundscripts in scripts/game_sounds_vo.txt.
2. the vcd file directly doesn't exist. This is the case for some responses added for Comp mode in the MyM Update. As they weren't supposed to
be showed in the match, only in the match outcome, they don't have a corresponding .vcd file (or perhaps I couldn't find it).