Spelcify licenses GPLv2 and LGPLv2.1

Signed-off-by: Kakadu <Kakadu@pm.me>

Bump lower bound of OCaml to 4.14

We are using Out_channel module in config/discover.ml

Signed-off-by: Kakadu <Kakadu@pm.me>

Improve lower dep of Camlp5 => perl is no longer needed

Signed-off-by: Kakadu <Kakadu@pm.me>

Relax constraint of ppxlib

Signed-off-by: Kakadu <Kakadu@pm.me>

OPAM file: add license

Signed-off-by: Kakadu <Kakadu@pm.me>

Specify dev-repo carefully

Signed-off-by: Kakadu <Kakadu@pm.me>

CI: trying to check installation

Upgrade samples

improve RTFD documentation

Signed-off-by: Kakadu <Kakadu@pm.me>

Fix opam file around tests

Signed-off-by: Kakadu <Kakadu@pm.me>