Make key extraction POSIX-compliant

Fix REQUEST_METHOD compare

Add HEAD support for cgi detection and add multiple play mode in fron…

Add basic CGI frontend for WSL

Added Gentoo install instructions

Add CGI support (fix #16)

so `FETCH="curl -s -k" dzr` could work while playing

Examples:

- `FETCH="wget -q -O -" dzr` use wget in place of curl
- `FETCH="curl -s -k" dzr` disable curl SSL verification

The last example is needed if you are behind a forward proxy

Add /user/:id menu on homepage