systemd: Import user session units v8 from Auke Kok

Import from git://github.com/sofar/user-session-units.git#refs/tags/v8 .
systemd: Add notification-daemon.service
systemd: Add nm-applet.service
systemd: Add tint2.service
systemd: Add xcompmgr.service
service: Add virtual panel.target
systemd: Add virtual kiwi-desktop.target
gnome-session: Fix null session

A gnome session must have some RequiredProviders and RequiredComponents.
Otherwise, otherwise you get the Fail Whale Sad Face screen.
gnome-session: Choose null.session

This prepares for switching over to systemd user sessions. There, the gnome
session will not spawn any DefaultProvides or RequiredComponents, so the session
file should be nearly empty. Systemd will spawn those as services.
gnome-session: Rename dummy componenets 'pacifier*' -> 'null*'

Naming them "null" makes it immediately clear what they do (or rather, what they
do not do).
applications: Change install method 'files' -> 'rsync'

It's safe to use rsync here as long as we don't use --delete. Otherwise, the
target directory gets clobbered, which is bad for ~/.local/share/applications.
gnome-session: Add gnome-fallback.session link

To have a full gnome desktop when not using gnome-shell (for example, when using
openbox), the autostart desktop files in /etc/xdg/autostart with the following
condition must be started:
    AutostartCondition=GNOME3 if-session gnome-fallback

Therefore, we must set
    org.gnome.desktop/session-name='gnome-fallback'

If using a systemd user session to manage the session, though, then
gnome-fallback.session must be a no-op. So this patch adds the symlink
    gnome-fallback.session -> null.session
redshift: Add helsinki.conf
redshift: Rename active.conf -> default.conf

The name 'default' seems to be more standard than 'active', mainly because of
systemd's usage of 'default.target'.
redshift: Add systemd service kiwi-gtk-redshift.service
tint2: Choose soft-translucent.tint2rc
profile: Refactor ascii colors to allow greater combinations

The color variables defined in 10-colors.sh did not allow for all
colorcombinations of face/background/foreground. This refactor allows all
combinations.

The achievable combinations were limited because each variable defined
a combination (for example, "$color_fg_bold_blue") and it was unfeasible
to define variables to cover the full combinatorial space. The refactor
decomposes the color definition into three variables: face, foreground,
background (for example,
"e[${kw_color_face_bold};${kw_color_bg_blue};${kw_color_fg_yellow}m".
less: Enable colored manpages

Set the necessary LESS_TERMCAP_* variables to color manpages. troff typeface
commands use more termcaps than enabled in this commit, but this is sufficient
to cover most of the typeface formatting.