Cherry-picked from 2faba794.

debian changes to 3.1

This sets LOCALE for the changelog generation from html with lynx
--dump, and sorts the md5sums list.

Formerly the output of --dump-config --verbose output could not be parsed.

(cherry picked from commit 8a65fcb4)

# Conflicts:
#	tests/check-configs

* Cope with version != Debian version
* 32-bit .deb builds are back
* Use gpg2 for signing

Haven't done a full GCC6 build so don't know if we're actually
clean.

https://bugs.debian.org/810335

https://bugs.debian.org/811705

(cherry picked from commit 480b2a71)

(cherry picked from commit fd1c7297c6e66f384fd0b310c528e4d73823091f)
(cherry picked from commit 9c3f7db9)

(cherry picked from commit 6ecf1ffafca419d1e193d96118a8abb0ff4ea7e3)
(cherry picked from commit 77a40912)

(cherry picked from commit c2720ab9aa90c15d4898e368e30684f58373de20)

This provides consistent mtimes and a build-dependency on pkg-config.

(cherry picked from commit b66537c5)

#793716)

This is a build-reproducibility fix

(cherry picked from commit edab4d16)

installing the postrm and postinst (so build is less sensitive to
source permissions)

(cherry picked from commit 4d36d211)

Conflicts:
	debian/control

(cherry picked from commit bc01ae2ea9eb34aa8be07e55cfe00108f935b0cb)

Needed for FreeBSD.

Include a --with{out}-lyx option for explicit control.

Not used in Store::identify because we need uid/gid and boost
won't tell us that.

CID 132880 (analyzer overcautious).

Actions probably shouldn't be copyable either since we take their
address, but some more work is needed before that can be done.