commands: Changed Request arguments to a []interface{}
core/commands2: Removed 'echo' test command
commands: Removed inpout stream from Request
commands: Fixed tests
commands/http: Added stream argument handling to client and request parser
commands: Renamed ArgPath to ArgFile
commands/cli: Open argument files when creating Requests (Moved out of HTTP client)
core/commands2: Added preliminary 'add' command
Added argument definition to 'cat' command