Enhance pause method flexibility (both C++ and JS)

sbbs_t::pause() and JS console.pause()...
now excepts an optional set_abort argument (default is true) which controls whether this method will set the global console-output aborted flag (sys_status&SS_ABORT in C++, console.aborted in JS) when the user hits the Quit or No key at the pause prompt.

This method now returns a bool: false if the user entered No, Quit, or Ctrl-C  at the pause prompt.

Nothing makes use of either of these new pause() features yet, but its generally better to not set/rely on global state wherever possible.