os/macos/ TmuxTerminfo

Summarised from here

1. Install ncurses (e.g. using Homebrew or Macports)
2. From that ncurses installation, generate the terminfo source file:

   infocmp -x tmux-256color >tmux-256color.info

3. Using the system ncurses (/usr/bin/tic, not just tic), compile the terminfo:

   /usr/bin/tic -xe tmux-256color tmux-256color.info

   (At this point you can delete the tmux-256color.info file.)