Gio: Add TcpWrapperConnection.

* tools/extra_defs_gen/genererate_defs_gio.cc:
  Add G_TCP_WRAPPER_CONNECTION.
* gio/src/gio_signals.defs: Regenerate this to add the signals
  for GTcpWrapperConnection.
* gio/src/filelist.am:
* gio/src/tcpwrapperconnection.[hg|ccg]:
  Add TcpWrapperConnection.

Markus Kolb noticed that this was missing.
* gio/giomm.h: Include tcpwrapperconnection.h