Represent incoming headers in proper Python objects on event handler, except for Authorization/Authenticate headers

darcs-hash:20081215151157-58103-db2cdb70be4197439c7981b1258cfad132977282
Removed "initial_" prefix from Engine init options

darcs-hash:20081216121934-58103-47b59e1e0292cfa6f71038abf150a4e8927a2ed8