zsh: make color_map and attr_map more robust

zsh allows to defile "global aliases" which may appear anywhere on the
command line. The most prominent example is:

  alias -g 'L'=" | less "

This allows command lines such as "bzr log L".

In order to avoid such global aliases to be expanded in this
user-sourced utility file, the key need to be quoted.
byobu-reconnect-sockets: quote shell expansions

this avoids error messages in zsh
* usr/bin/byobu-janitor:
  - there is no "grey" in tmux
* usr/bin/byobu-launch:
  - append, rather than prepend, $PROMPT_COMMAND, as double-semi-colons
    are illegal, thanks to Christian Mäder in github for patch
* usr/bin/byobu, usr/lib/byobu/include/Makefile.am,
  usr/lib/byobu/include/tmux-detach-all-but-current-client,
  usr/share/byobu/keybindings/f-keys.tmux,
  usr/share/byobu/keybindings/f-keys.tmux.disable,
  usr/share/doc/byobu/help.tmux.txt: LP: #939870
  - add a new keybinding, Alt-F6, which detaches all other clients
    + often used to maximize your tmux session, since tmux reduces
      the available size of your terminal to the smallest connected
      session
usr/bin/byobu-janitor: LP: #1173620
* usr/bin/byobu: LP: #1176956
  - handle unlimted ulimits
* usr/bin/byobu-reconnect-sockets, usr/lib/byobu/include/shutil: LP: #1162432
  - fix reconnect on zsh
* usr/share/man/man1/byobu.1: LP: #1121414
  - document PuTTY UTF-8 configuration
    + thanks to Chris Holmes
* usr/bin/byobu-keybindings, usr/bin/Makefile.am,
  usr/share/man/man1/byobu-keybindings.1,
  usr/share/man/man1/Makefile.am: LP: #1118755
  - added a new executable and manpage: byobu-keybindings
  - this is a command line utility for toggling Byobu's keybindings
    on an off
  - useful when Shift-F12 is not usable (Linux console tty), and
    when ctrl-a-! is not usable (tmux)
* usr/bin/byobu-ctrl-a: LP: #1045070
  - check if the user has already chosen an escape sequence and if so,
    don't bother them with the ctrl-a question
releasing 5.38
opening 5.39
* usr/bin/byobu:
  - fix minor syntax error
not sure if I want this in F5 yet or not...
releasing 5.39
opening 5.40
* usr/share/byobu/profiles/tmux: LP: #1177728
  - use byobu's tmux-screen-keys.conf
* debian/postinst: LP: #1174537
  - drop the env python changes in the postinst
* debian/control, usr/bin/byobu-select-profile: LP: #1166416
  - hardcode a use of gawk (for hex calculations)