allow executing a command in the new terminal widget * command-widget.cc (console::new_command_line): Allow a new command line with preset text; (console::execute_command): Slot for executing a command * command-widget.h, class console: new_command_line with optional string argument, new functions execute_command and get_console * main-window.cc (adopt_terminal_widget): connect execute command signal with related signal in terminal widget; (execute_command_in_terminal): in case of exp. terminal widget, emit new signal execute_command_signal * main-window.h: new signal execute_command_signal * terminal-dock-widget.cc (terminal_dock_widget): connect own execute signal to the slot in the console * terminal-dock-widget.h: new signal execute_command_signal

Things to do before making a release:

  * Update the version number and release date in configure.ac.

  * Update the OCTAVE_API_VERSION number in configure.ac.

  * Update version number and release year in CITATION.

  * Update the etc/NEWS.N.md file corresponding to the major release
    number N.  Include release date in Summary header.

  * Update the NEWS-<VERSION>.html, index.in, news.in, and download.in
    files for the web site.

  * Copy tarballs to ftp.gnu.org.

  * Post a release announcement to the help@octave.org and
    info-gnu@gnu.org lists.

  * Update https://wiki.octave.org/Release_History page.