The first existing file of the following paths is loaded:
- /home/username/.config/exampleapp/config
- /etc/xdg/exampleapp/config

This can be influenced with the following environment variables:
- XDG_CONFIG_HOME
- XDG_CONFIG_DIRS
- EXAMPLEAPP_CONFIG_PATH
- EXAMPLEAPP_CONFIG_DIRECTORY
- EXAMPLEAPP_CONFIG_NAME

You can also use environment variables to change the values of the
settings listed under `set` command. The corresponding environment
variable name is the name of the setting in all upper case letters
with dots, hypens and spaces replaced by underscores and prefixed with
"EXAMPLEAPP_".

Lines in the config file which start with a `"` or `#` are ignored.

The config file may contain the following commands:

set
===
usage: set [--raw] key1=val1 [key2=val2 ...]
       set [--raw] key [=] val

Change the value of a setting.

In the first form set takes an arbitrary number of arguments, each
argument sets one setting. This has the advantage that several
settings can be changed at once. That is useful if you want to bind a
set command to a key and process that command with
ConfigFile.parse_line() if the key is pressed.

In the second form set takes two arguments, the key and the value.
Optionally a single equals character may be added in between as third
argument. This has the advantage that key and value are separated by
one or more spaces which can improve the readability of a config file.

You can use the value of another setting with %other.key% or an
environment variable with ${ENV_VAR}. If you want to insert a literal
percent character use two of them: %%. You can disable expansion of
settings and environment variables with the --raw flag.

data types:

  int:
    An integer number in python 3 syntax, as decimal (e.g. 42),
    hexadecimal (e.g. 0x2a), octal (e.g. 0o52) or binary (e.g.
    0b101010). Leading zeroes are not permitted to avoid confusion
    with python 2's syntax for octal numbers. It is permissible to
    group digits with underscores for better readability, e.g.
    1_000_000.

settings:

  answer:
    an int

    42: The answer to everything
    23: The natural number following 22 and preceding 24

  color.background:
    one of red, green, blue

  color.foreground:
    one of red, green, blue

include
=======
usage: include path

Load another config file.

This is useful if a config file is getting so big that you want to
split it up or if you want to have different config files for
different use cases which all include the same standard config file to
avoid redundancy or if you want to bind several commands to one key
which executes one command with ConfigFile.parse_line().

positional arguments:
  path  The config file to load. Slashes are replaced with the
        directory separator appropriate for the current operating
        system. If the path contains a space it must be wrapped in
        single or double quotes.

echo
====
usage: echo [-l {info,error}] [-r] msg [msg ...]

Display a message.

Settings and environment variables are expanded like in the value of a
set command.

positional arguments:
  msg                   The message to display

options:
  -l {info,error}, --level {info,error}
                        The notification level may influence the
                        formatting but messages printed with echo are
                        always displayed regardless of the
                        notification level.
  -r, --raw             Do not expand settings and environment
                        variables.

help
====
usage: help [cmd]

Display help.

positional arguments:
  cmd  The command for which you want help
