add "mime" and "default type" option for the configuration

improve mime handling we still have an hardcoded list, but this implements the API needed to modify the mappings.

removing err/warn functions with our fatal err/warn is not available on some systems (unfortunately!) and in any case don't play well with our daemon mode (that closes std{in,out,err}). Use our fatal that is daemon-aware.

fix requri construction when we switched from one process to two, I introduced a small optimisation: empty string are not send, so we receive NULL. Constructing requri we need to make sure that relpath is not null.

removing O_CLOEXEC we don't fork anymore in that process, so the flag is extra.

removed

reorganize: move bunch of functions to server.c cgi.c wasn't really needed; it better to group all the server related functions together, cgi or not. Now gmid.c contains only startup and utility code.

mention libretls

[seccomp] allow also poll on the latest fedora we glibc uses poll. On the other linux distro I tried (void), musl is probably providing poll as a ppoll wrapper.

build docs + install and static targets

re-enable daemon mode with the split into two process, the call to daemon was lost

fix runtime test on linux

add runtime tests for the server

grammar

sync changes