Add content to "Java EE 8" page

[OndroMih]

add pointers to latest efforts with Java EE 8 (Glassfish 5 and JSRs in development, Payara 5, https://javaee8.zeef.com/arjan.tijms)

[OndroMih]

Also add link to this repo with JavaEE specs: https://github.com/javaee-spec