Update script web server checking.
- Install script now checks which web servers are installed and asks which to use and whether to disable the other if there are multiple.
- If only one web server is installed, it uses it by default. This will be apache2 if no web server was installed initially, due to PHP installing apache2.
- Update script updated to accomodate 0.4.0-beta and 0.4.1-beta. 0.4.1-beta and 0.4.2-beta are the same.