Its "dwm" not "DWM"

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.

- Added the $IDENTIFIER value that determines if unicode or plaintext is
used for function identifiers
- Cleaned up scripts with the help of shellchecker
- Fixed dwm_status so that other drives mounted within /home are ignored
- Replaced unicode codes with actual unicode in the source. For some
reason the codes didnt work on my Void machine
- Updated readme