tmux: Enable mouse scrolling, windown and pane select. Also provides a binding to disable/enable mouse for copy/pase.

.tmux.conf

# mouse-mode
set-window-option -g mode-mouse on
set-option -g mouse-resize-pane on
set-option -g mouse-select-pane on
set-option -g mouse-select-window on

# toggle mouse mode to allow mouse copy/paste
# set mouse on with prefix m
bind m \
    set -g mode-mouse on \;\
    set -g mouse-resize-pane on \;\
    set -g mouse-select-pane on \;\
    set -g mouse-select-window on \;\
    display 'Mouse: ON'

# set mouse off with prefix M
bind M \
    set -g mode-mouse off \;\
    set -g mouse-resize-pane off \;\
    set -g mouse-select-pane off \;\
    set -g mouse-select-window off \;\
    display 'Mouse: OFF'