Log Message:
Update mlterm to 3.4.5.

Changes noted in doc/en/ReleaseNote:

ver 3.4.5
* Fix a bug which disabled to start mlconfig. (Enbugged at 3.4.4)
* Fix hangup when mlconfig exits on cygwin+win32gdi+libssh2.
* Enable to open a framebuffer device even if normal users aren't permitted to
  open it on Linux, FreeBSD and {Net|Open}BSD/wscons.

ver 3.4.4
* Support DECBI(ESC 6), DECFI(ESC 9), DECIC(CSI'}), DECDC(CSI'~), DECST8C(CSI?W),
  DECSACE(CSI*x), DECRARA(CSI$t) and DECCARA(CSI$r).
* libvte compatible library supports vte-2.91 API. (vte 0.38 or later)
* Change the default value of --with-gtk of configure script from 2.0 to 3.0.
* Change the default value of "use_clipboard" option from \ 
"false" to "true".
* Show message on screen if you change settings by "proto:" shortcut.
* OPEN_SCREEN or OPEN_PTY shortcut key opens pty with the same char encoding and
  executes the same command as the current screen connecting to a remote host \ 
via libssh2.
* OSC 5380 without challenge doesn't return "#forbidden" but shows \ 
"key=value" on
  the screen temporarily.
* "Alt" which equals to "Mod" is available in ~/.mlterm/key.
* Bug fixes:
  Fix unexpected erasure at the bottom line of the screen if you use gnome-terminal
  3.6.2 with libvte compatible library.
  Fix segfault in opening multiple ptys with the use of gnome-pty-helper.
  Fix error in compiling mlconfig with gtk+-3.x and libssh2.
  Fix saving wrong character set by DECSC etc if --boxdraw=unicode option is \ 
specified.