VIM: use mixed sign/number column

vim/.vimrc

@@ -20,6 +20,7 @@ filetype plugin on
 filetype plugin indent on
 
 set encoding=utf-8
+set signcolumn=number
 
 set foldmethod=syntax
 

vim/config/pluginconfig.vim

@@ -95,7 +95,6 @@ set nowritebackup
 set cmdheight=2
 set updatetime=300
 set shortmess+=c
-set signcolumn=yes
 " Use tab for trigger completion with characters ahead and navigate.
 " Use command ':verbose imap <tab>' to make sure tab is not mapped by other plugin.
 inoremap <silent><expr> <TAB>