Add sign_priority option

Author: qbedard

autoload/sy/sign.vim

@@ -229,10 +229,11 @@ function! s:add_sign(sy, line, type, ...) abort
           \ a:1,
           \ s:delete_highlight[g:signify_line_highlight])
   endif
-  execute printf('sign place %d line=%d name=%s buffer=%s',
+  execute printf('sign place %d line=%d name=%s priority=%d buffer=%s',
         \ id,
         \ a:line,
         \ a:type,
+        \ get(g:, 'signify_priority', 10),
         \ a:sy.buffer)
 
   return id

doc/signify.txt

@@ -135,6 +135,7 @@ default values, as long as no "Default:" section is given.
     |g:signify_sign_show_text|
     |g:signify_difftool|
     |g:signify_fold_context|
+    |g:signify_priority|
 
 ------------------------------------------------------------------------------
                                                             *g:signify_vcs_cmds*  >
@@ -321,6 +322,14 @@ unfolded. Using |zo| (and similar |fold-commands|) on a folded line will reveal
 
 Default: [3, 8]
 
+------------------------------------------------------------------------------
+                                                        *g:signify_priority*  >
+    let g:signify_priority = 5
+<
+This changes the sign priority used for signs. See |sign-priority|.
+
+Default: 10
+
 ==============================================================================
 COMMAND                                                       *signify-commands*
                                                         *signify-:SignifyEnable*  >