v0.16

Fix reverse shell I/O and add request timeouts

• rev_shell: decode recv() bytes before writing to stdout and encode
  outgoing input with a trailing newline. Previously both raised
  TypeError (bytes->stdout, str->socket) and commands were never
  terminated, so the reverse shell could break.
• send_payload: add a configurable request timeout (cfg.timeout,
  default 30s) to the GET/POST/form requests, which previously had
  none and would block indefinitely on a hung target.