replace runtime! calls with source

- See:
- src/main.c - for plugin loading
- src/ex_cmds2.c - for how :runtime! and :source work

- benefit of using source vs runtime is that it's faster as doesn't
traverse &rtp

autoload/vundle/config.vim

@@ -13,15 +13,19 @@ endf
 
 func! vundle#config#require(bundles) abort
   for b in a:bundles
+    " TODO: should this be here?
     call s:rtp_add(b.rtpath())
-    call s:rtp_add(g:vundle#bundle_dir)
-    " TODO: it has to be relative rtpath, not bundle.name
-    exec 'runtime! '.b.name.'/plugin/*.vim'
-    exec 'runtime! '.b.name.'/after/*.vim'
-    call s:rtp_rm(g:vundle#bundle_dir)
+    " load plugin
+    for s in s:glob(b.rtpath().'/plugin/**/*.vim')
+      exec 'source '.s
+    endfor
   endfor
 endf
 
+func! s:glob(pattern)
+  return split(glob(a:pattern),"\n")
+endf
+
 func! vundle#config#init_bundle(bang, name, opts)
   let opts = extend(s:parse_options(a:bang, a:opts), s:parse_name(substitute(a:name,"['".'"]\+','','g')),'keep')
   return extend(opts, copy(s:bundle))