* install.py: Integrate waterfox and default to firefox user.js always
This commit:
- Removes the old --zen switch
- Adds a new --browser/-b switch to specify the browser. Available
options: firefox, waterfox, zen
- Now defaults to the firefox user.js even if there's new user.js added
* install.py: Remove the redundant --zen flag
* install.py: add shebang
* install.py: remove old version of _get_firefox_version
* install.py: search for Firefox installation, including flatpak version
* install.py: add option to disable 'Press ENTER to exit'
* install.py: fix windows root
minh2134