updated tpm integration

- automatically delete tpm when not used
- automatically delete unused plugins
- install plugins when subsequently enabling then in ~/.tmux.conf.local
- use <prefix> + u to update plugins as <prefix> + U is bound to Urlview, fixes #507

.tmux.conf.local

@@ -367,6 +367,17 @@ tmux_conf_update_plugins_on_launch=true
 #   - false
 tmux_conf_update_plugins_on_reload=true
 
+# by default, reloading the configuration will uninstall tpm and plugins when no
+# plugins are enabled
+#   - true (default)
+#   - false
+tmux_conf_uninstall_plugins_on_reload=true
+
+# /!\ the tpm bindings differ slightly from upstream:
+#   - installing plugins: <prefix> + I
+#   - uninstalling plugins: <prefix> + Alt + u
+#   - updating plugins: <prefix> + u
+
 # /!\ do not add set -g @plugin 'tmux-plugins/tpm'
 # /!\ do not add run '~/.tmux/plugins/tpm/tpm'