Welease 26.

Die if a release method is unknown, rather than warning.

Reorder code so we check methods are known and prompt for missing
release notes before checking we have all needed variables.

Remove support for getinfo methods, as none of the current release
methods have them.
Fix grep call broken in last commit.
Add a FIXME.
Split luarocks method out of lua method (which still calls it), and allow rock release to be given.