Resolve conflicts between iris.sty and acmart

\nequiv and \state now both exist in acmart so we have to pick different names.

sed script for fixing documents:

sed -i -E -f- *.tex <<EOF
s/\\\nequiv(\b|_)/\\\dist\1/g
s/\\\nincl(\b|_)/\\\subseteqN\1/g
s/\\\notnequiv(\b|_)/\\\ndist\1/g
s/\\\nequivset(\b|_)/\\\distset\1/g
s/\\\state(\b|_)/\\\pstate\1/g
EOF

Fixes #335 (closed)