laszip: fix maintainer reference

This unblocks the channel.
gpgme: update from 1.4.3 to 1.5.1
gtkspell3: update from 3.0.4 to 3.0.6
hatari: update from 1.6.2 to 1.8.0
imapfilter: update from 2.5.4 to 2.5.6
libgpgerror: update from 1.12 to 1.13
libpng15: update from 1.5.18 to 1.5.19
libpng: use spdx licensing method
opusTools: update from 0.1.8 to 0.1.9
opusfile: update from 0.4 to 0.6
orc: update from 0.4.21 to 0.4.22
rlwrap: update from 0.37 to 0.41
thunderbird-bin: update from 31.0 to 31.1.1, potentially fixes CVE-2014-1553, CVE-2014-1562, CVE-2014-1563, CVE-2014-1564, CVE-2014-1565, CVE-2014-1567
pius: update from 2.0.9 to 2.0.11
slang: update from 2.2.1 to 2.3.0
Hopefully update all thunderbird-bin sources
Various SLIM themes, obtained from Sourceforge's SLIM website

Closes #3974
snd: update from 14.3 to 14.9
Ratpoison: updated for 1.4.8

Also, adding the infamous service file

Closes #4192
Add escoger, a terminal fuzzy selector.

default.nix was generated with cabal2nix, but modified to use GitHub as
the source since escoger isn't on Hackage.

Closes #4194