Since version 243, systemd-logind supports setting the brightness of an
"leds" or "backlight" kernel class device [1]. This method call requires
no privileges to call, but a caller can only change the brightness on
sessions that are currently active, and they must own the session.

Using systemd/elogind for unprivileged brightness changes is a nice
feature to have since it allows to changes brightness without giving
explicit permissions to users via groups or setting SUID bit.

[1] https://github.com/systemd/systemd/commit/2a66c2a1eda48433cb7f4ac6e9b9abcf4bd41bf3

Update debian/folder with the version in Debian

Update Ubuntu section with video group instructions

Added installation instructions for NixOS/nix

Improve coding style - consistency of not placing a whitespace after `if`, and `while`

Fix config path information

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Co-Authored-By: TheJakeSchmidt <TheJakeSchmidt@users.noreply.github.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Fix github light release link

The github releases page was wrong. This will help users to install light faster.

debian: install udev rules under /lib

Update installation instructions for Arch Linux

Introduce the concept of a float-typed value in the context, for commands
like -T that don't work with percentages/raw values.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Fix #66: Align man page with help text

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Update debian packaging

- Order commands and options similar to help text, not alphabetically
- Update command descriptions to new nomenclature
- Update copyright years

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Seeing as light supports at least two different GNU/Linux distributions
it seems prudent to not claim 'package:' for Debian packages.  This has
the added benefit of adding easy build targets for RedHat/Fedora, Arch,
and others.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

- Bump debhlper compat to >= 10 (Stretch)
- Update Standards-Version field, we seem to be compatible
- Update package Description filed, lintian complains of empty body
- Update changelog date and drop GitHub issue reference, confuses lintian

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>