issue #14: AEF::Server::Role::Auth to handle preauth command checking
issue #5: doco
issue #5: doco
issue #4: extract AEF::Server::Role::TransferPrep from AEF::Server::Context::Full
issue #5: doco
issue #4: use Moo style attributes
issue #4: AEF::Server::Context::FS class
issue #4: AEF::Server::Context::Full isa AEF::Server::Context::FS