Added TableModeEnabled & TableModeDisabled autocmd

* Added custom User autocmds TableModeEnabled & TableModeDisabled for
  working with other plugins like vim-pandoc #43

autoload/tablemode.vim

@@ -97,7 +97,11 @@ function! s:SetActive(bool) "{{{2
   let b:table_mode_active = a:bool
   call s:ToggleSyntax()
   call s:ToggleMapping()
-  if b:table_mode_active | echo "table-mode enabled" | else | echo "table-mode disabled" | endif
+  if tablemode#IsActive()
+    doautocmd User TableModeEnabled
+  else
+    doautocmd User TableModeDisabled
+  endif
 endfunction
 
 function! s:ConvertDelimiterToSeparator(line, ...) "{{{2