DEBUG: unstatify a few functions that are often present in backtraces

DEBUG: unstatify a few functions that are often present in backtraces

It's useful to be able to recognize certain functions that are often
present in backtraces as they call lower level functions, and for this
they must not be static. Let's remove "static" in front of these
functions:

  sc_notify, sc_conn_recv, sc_conn_send, sc_conn_process,
  sc_applet_process, back_establish, stream_update_both_sc,
  httpclient_applet_io_handler, httpclient_applet_init,
  httpclient_applet_release