fix how int64_t is print in parse.y

allow to speak "TLS-less Gemini" useful for e.g. to save some CPU cycles when the Gemini server is sitting on the same box as Galileo; disabled by default.

error if no proxies are defined

error on duplicate proxies

use %token and not %type for NUMBER and STRING

error if no `source' is defined for a proxy

default `hostname' to the source host

make the port number optional and keep it as string

simplify the configuration format don't require the awkward `server' block, just use a `proxy' block: proxy { source address port xyz hostname foo stylesheet "URL" }

link the specified stylesheet (if any)

initial import