Add ToggleMRURelative

Closes #398

autoload/ctrlp.vim

@@ -937,6 +937,11 @@ fu! s:ToggleKeyLoop()
 	en
 endf
 
+fu! s:ToggleMRURelative()
+	cal ctrlp#mrufiles#tgrel()
+	cal s:PrtClearCache()
+endf
+
 fu! s:PrtSwitcher()
 	let [s:force, s:matches] = [1, 1]
 	cal s:BuildPrompt(1)

autoload/ctrlp/mrufiles.vim

@@ -126,6 +126,10 @@ fu! ctrlp#mrufiles#bufs()
 	retu s:mrbs
 endf
 
+fu! ctrlp#mrufiles#tgrel()
+	let {s:re} = !{s:re}
+endf
+
 fu! ctrlp#mrufiles#cachefile()
 	if !exists('s:cadir') || !exists('s:cafile')
 		let s:cadir = ctrlp#utils#cachedir().ctrlp#utils#lash().'mru'

doc/ctrlp.txt

@@ -572,6 +572,9 @@ Example: >
 Set this to 1 to show only MRU files in the current working directory: >
   let g:ctrlp_mruf_relative = 0
 <
+Note: you can use a custom mapping to toggle this option inside the prompt: >
+  let g:ctrlp_prompt_mappings = { 'ToggleMRURelative()': ['<F2>'] }
+<
 
                                                  *'g:ctrlp_mruf_default_order'*
 Set this to 1 to disable sorting when searching in MRU mode: >