Refactor PR code order to not move cheese

With tons of outstanding PRs I don't want to introduce conflicts for no
reason. We can refactor to make the source order more sensible later.

plugin/vimux.vim

@@ -3,14 +3,6 @@ if exists("g:loaded_vimux") || &cp
 endif
 let g:loaded_vimux = 1
 
-function! _VimuxOption(option, default)
-  if exists(a:option)
-    return eval(a:option)
-  else
-    return a:default
-  endif
-endfunction
-
 function! _VimuxTmuxCmd()
   return _VimuxOption("g:VimuxTmuxCommand", "tmux")
 endfunction
@@ -202,6 +194,14 @@ function! _VimuxRunnerType()
   return _VimuxOption("g:VimuxRunnerType", "pane")
 endfunction
 
+function! _VimuxOption(option, default)
+  if exists(a:option)
+    return eval(a:option)
+  else
+    return a:default
+  endif
+endfunction
+
 function! _VimuxTmuxProperty(property)
     return substitute(_VimuxTmux("display -p '".a:property."'"), '\n$', '', '')
 endfunction