Improve loading time when matchparen_enabled=0

Also be more robust in loading pi_paren's plugin/matchparen.vim
cf. #25, cf. SpaceVim/SpaceVim/#1482

autoload/matchup.vim

@@ -61,6 +61,9 @@ endfunction
 
 function! s:init_modules()
   for l:mod in [ 'loader', 'matchparen' ]
+    if !get(g:, 'matchup_'.l:mod.'_enabled', 1)
+      continue
+    endif
     call matchup#perf#tic('loading_module')
     call matchup#{l:mod}#init_module()
     call matchup#perf#toc('loading_module', l:mod)

autoload/matchup/matchparen.vim

@@ -21,6 +21,8 @@ endfunction
 " }}}1
 
 function! matchup#matchparen#enable() " {{{1
+  let g:matchup_matchparen_enabled = 1
+
   if g:matchup_matchparen_deferred
         \ && (!has('timers') || !exists('*timer_pause')
         \     || has('nvim') && !has('nvim-0.2.1'))
@@ -40,8 +42,6 @@ function! matchup#matchparen#enable() " {{{1
       autocmd TextChangedP * call s:matchparen.highlight_deferred()
     endif
     autocmd WinLeave * call s:matchparen.clear()
-    " autocmd BufLeave * call s:matchparen.clear()
-    " autocmd InsertEnter,InsertLeave  * call s:matchparen.highlight()
     autocmd InsertEnter * call s:matchparen.highlight(1, 1)
   augroup END
 
@@ -86,8 +86,9 @@ let s:pi_paren_sid = -1
 " }}}1
 
 function! matchup#matchparen#disable() " {{{1
+  let g:matchup_matchparen_enabled = 0
   call s:matchparen.clear()
-  autocmd! matchup_matchparen
+  silent! autocmd! matchup_matchparen
 endfunction
 
 " }}}1
@@ -96,9 +97,10 @@ function! matchup#matchparen#toggle(...) " {{{1
         \ ? a:1
         \ : !g:matchup_matchparen_enabled
   if g:matchup_matchparen_enabled
+    call matchup#matchparen#enable()
     call s:matchparen.highlight(1)
   else
-    call s:matchparen.clear()
+    call matchup#matchparen#disable()
   endif
 endfunction
 

plugin/matchup.vim

@@ -30,14 +30,18 @@ if exists('g:loaded_matchit')
 endif
 let g:loaded_matchit = 1
 
-if get(g:, 'matchup_matchparen_enabled', 1)
-  if !exists('g:loaded_matchparen')
-    runtime plugin/matchparen.vim
-  endif
+" ensure pi_paren is loaded but deactivated
+try
+  runtime plugin/matchparen.vim
   au! matchparen
-  command! NoMatchParen call matchup#matchparen#toggle(0)
-  command! DoMatchParen call matchup#matchparen#toggle(1)
-endif
+catch /^Vim\%((\a\+)\)\=:E216/
+  unlet! g:loaded_matchparen
+  runtime plugin/matchparen.vim
+  silent! au! matchparen
+  let g:loaded_matchparen = 1
+endtry
+command! NoMatchParen call matchup#matchparen#toggle(0)
+command! DoMatchParen call matchup#matchparen#toggle(1)
 
 if get(g:, 'matchup_override_vimtex', 0)
   let g:vimtex_matchparen_enabled = 0