Multiple ports: improve regex compliance (part 2)

This is again a part of the project to stop extraneous escaping of
ordinary characters and redefine some ordinary escapes as special
behavior.

Most of these ports are pushed over to use textproc/gsed because they
want to use GNU extensions. Others are fixed to either escape appropriately
(e.g. $$ rather than \$ in Makefiles!) or just remove redundant escapes
(e.g. backtick in single quotes doesn't need escaped).

PR: 229925
MFH: no (invasive risk)