Start making improvements to tmux.conf; some depend on recent tmux versions

Will need to see if we can guard those.

tmux.conf

@@ -1,11 +1,65 @@
+# Bind tmux prefix to Ctrl-B
+set -g prefix C-b
+
+# But give us a way to send it through if necessary.
+bind C-b send-prefix
+
+# Start window numbering at 1, not 0.
 set -g base-index 1
 
+# Same for panes, to be consistent.
+set -w -g pane-base-index 1
+
 # run-shell ~/src/tmux-resurrect/resurrect.tmux
 
 bind C-l send-keys 'C-l'
 
-bind r source ~/.tmux.conf\; display "~/.tmux.conf sourced!"
-bind-key P command-prompt -p 'save history to filename:' -I '~/tmux.history' 'capture-pane -S -32768 ; save-buffer %1 ; delete-buffer'
+bind r \
+  source ~/.tmux.conf\; \
+  display "Configuration reloaded."
+
+# Save entire pane history to a file.
+bind-key P \
+  command-prompt -p 'save history to filename:' -I '~/tmux.history' 'capture-pane -S -32768 ; save-buffer %1 ; delete-buffer'
+
+# Turn on focus events, used by (for example) Vim.
+set -g focus-events on
+
+# Reduce time waited to see if a key is escape alone or an escape sequence.
+set -sg escape-time 10
+
+# Easier to remember keys for splitting panes.
+bind | split-window -h
+bind - split-window -v
+
+# Additional pane navigation.
+bind h select-pane -L
+bind j select-pane -D
+bind k select-pane -U
+bind l select-pane -R
+
+# And resizing, with repeatable bindings.
+bind -r H resize-pane -L 5
+bind -r J resize-pane -D 5
+bind -r K resize-pane -U 5
+bind -r L resize-pane -R 5
+
+# I'm not a keyboard fanatic; enable the mouse.
+set -g mouse on
+
+# Enable the pretty colours...
+# If there are problems with outdated ncurses's's's, we can use "screen-256color" instead.
+set -g default-terminal "tmux-256color"
+
+# Override terminal for 32-bit RGB colour. (Disabled for now, need to test with MobaXterm.)
+# set -a terminal-overrides ",*256col*:RGB"
+
+# Make it obvious which pane we're in.
+set -w -g pane-active-border-style fg=black,bg=color140
+set    -g pane-border-indicators   arrows
+
+# Give the panes their own status indicator.
+set -g pane-border-status top
 
 # List of plugins
 set -g @plugin 'tmux-plugins/tpm'
@@ -24,12 +78,6 @@ set -g @plugin 'seebi/tmux-colors-solarized'
 set -g @resurrect-strategy-vim 'session'
 set -g @continuum-restore 'on'
 
-# Turn on focus events, used by (for example) Vim.
-set -g focus-events on
-
-# Reduce time waited to see if a key is escape alone or an escape sequence.
-set -sg escape-time 10
-
 # Initialize TMUX plugin manager (keep this line at the very bottom of tmux.conf)
 run -b '~/.tmux/plugins/tpm/tpm'