Make vim Zenmode toggleable

vim/plugin/zen.vim

@@ -1,10 +1,26 @@
+function s:loadState(state)
+	for name in keys(a:state)
+		exec "let" name.'="'.a:state[name].'"'
+	endfor
+endfun
+
+function s:dumpState(state)
+	let l:newstate = {}
+	for name in keys(a:state)
+		exec "let l:newstate[\"".name."\"]=".name
+	endfor
+	return l:newstate
+endfun
+
+let s:state = { "&number": "0", "&relativenumber": "0", "&colorcolumn": "0", "&laststatus": "0", "&fillchars": "eob:\\ " }
+
 function Zen()
-	set nonumber
-	set norelativenumber
-	set colorcolumn=0
-	set laststatus=0
-	if has("nvim")
-		set fillchars=eob:\ 
+	if exists("g:zenState")
+		call s:loadState(g:zenState)
+		unlet g:zenState
+	else
+		let g:zenState = s:dumpState(s:state)
+		call s:loadState(s:state)
 	end
 endfun