Changed TCSAFLUSH to TCSANOW

In all cases the pattern was tcflush(fd, TCIOFLUSH) followed by
tcsetattr(fd, TCSAFLUSH, ...). The problem was that, for some drivers,
tcflush() was apparently doing nothing, so tcsetattr() might hang
forever waiting for the output buffers to drain (possible if flow
control is enabled). Replaced tcflush(fd, TCSAFLUSH), with tcsetattr(fd,
TCSANOW) which, after a tcflush() should anyway be equivalent.

term.h

@@ -305,13 +305,17 @@ int term_replace (int oldfd, int newfd);
  * associated with the managed filedes "fd", to the respective
  * terminal device.  It then re-reads the settings form the device and
  * stores them in "nexttermios". Finally it copies "nexttermios" to
- * "currtermios".
+ * "currtermios". If "now" is not zero, settings are applied
+ * immediatelly, otherwise setting are applied after the output
+ * buffers are drained and the input buffers are discarder. In this
+ * sense, term_apply(fd, 0) is equivalent to: term_drain(fd);
+ * term_flush(fd); term_apply(fd, 1);
  *
  * Returns negative on failure, non negative on success. In case of
  * failure the "nexttermios" and "currtermios" structures are not
  * affected.
  */
-int term_apply (int fd);
+int term_apply (int fd, int now);
 
 /*
  * F term_revert