Multiple small updates for tmux and vim

vim/system.vim

@@ -0,0 +1,22 @@
+" Revert settings that Debian might have touched
+if $VIM !=# '/usr/share/vim' || !filereadable('/etc/debian_version')
+  finish
+endif
+
+" Set options back to appropriate defaults
+set history&
+set suffixes&
+if has('cmdline_info')
+  set ruler&
+endif
+if has('printoptions')
+  set printoptions&
+endif
+
+" Restore terminal settings to reflect terminfo
+set t_Co& t_Sf& t_Sb&
+
+" Remove addons directories from 'runtimepath' if present
+set runtimepath-=/var/lib/vim/addons
+set runtimepath-=/var/lib/vim/addons/after
+