Small slime hack

* etc/emacs/common/50slime.el (slime): define C-c C-k to nil in slime-mode-map.
Look and feel tweaks

* etc/emacs/common/50extra.el (joaot/unfill-region): Nicer joaot/unfill-region

* etc/emacs/common/80external.el (el-get-sources): don't start unstable
`flx-ido-mode', use two new themes.
Misc siscog hacks

* etc/emacs/siscog/50address-book.el (siscog/ido-complete-name): fix this.
(siscog/address-book): update address-book.

* etc/emacs/siscog/50different-ack.el (ack-and-a-half): Advise ack-and-a-half to
use correct whell.

* etc/emacs/siscog/50slime-tricks.el (inferior-lisp-program): Set inferior-lisp
program to use sc-sly and acl90.
Remove two useless zsh files

* etc/zsh/common/40spectrum.zsh: remove

* etc/zsh/common/50prompt.zsh: remove
Do use cygwin PATH in siscog bash shells

* 50do-use-cygwin-with-bash.bash (PATH): do use cygwin path
mintty hack

* etc/everything-else/siscog/solarized-dark.mintty (Transparency): turn off transparency
Rebind `joaot/kill-this-buffer'

* etc/emacs/common/50look-and-feel.el (kbd): `joaot/kill-this-buffer' is now bound
to "C-x C-k". This is going to take some time to get used to...