it is possible to use `--get-volume` to avoid having to strip the percent sign

Connman is a lightweight network manager.
With this patch basic network information like SSID, WLan signal
strength and IP can be provided to the dwm-bar.

For portability, sh allows the script to run on other shells set by the user. This has been tested on Bash and Posix sh and still functions using them.

The 'SEP' contain the charachter(s) that are placed before and after a
module (respectively). For example, if SEP1="[" and SEP2="]" then each
module will be surrounded by those charachters.

Add dwm_backlight that displays the value of
xbacklight rounded to the nearest int.

- Individual functions no longer contain the square brackets to act as
seperators. These are instead included in the xsetroot command within
dwm_bar.sh itself so that they can be modified much more easily if the user desires.
- Fixed dwm_battery.sh showing a space between the level and '%' symbol
when discharging.
- Added dwm_ccurse to dwm_bar.sh. Guess I forgot that.