Enable silencing automatic periodic sessions saving

Refer to issue 120 on GitHub for details:
  #120

Author: xolox

README.md

@@ -162,6 +162,10 @@ This option sets the interval in minutes for automatic, periodic saving of activ
 
 Note that when the plug-in automatically saves a session (because you enabled this feature) the plug-in will not prompt for your permission.
 
+### The `g:session_autosave_silent` option
+
+If you set this option to true (1) the messages normally emitted by automatic, periodic saving of active sessions are silenced.
+
 ### The `g:session_verbose_messages` option
 
 The session load/save prompts are quite verbose by default because they explain how to disable the prompts. If you find the additional explanation distracting you can lower the verbosity by setting this option to 0 (false) in your [vimrc script] [vimrc].

autoload/xolox/session.vim

@@ -1,10 +1,10 @@
 " Public API for the vim-session plug-in.
 "
 " Author: Peter Odding
-" Last Change: March 15, 2015
+" Last Change: July 8, 2015
 " URL: http://peterodding.com/code/vim/session/
 
-let g:xolox#session#version = '2.10.1'
+let g:xolox#session#version = '2.11'
 
 " Public API for session persistence. {{{1
 
@@ -491,9 +491,18 @@ function! xolox#session#auto_save_periodic() " {{{2
       let name = xolox#session#find_current_session()
       if !empty(name)
         if xolox#session#is_tab_scoped()
-          call xolox#session#save_tab_cmd(name, '', 'SaveTabSession')
+          let function = 'xolox#session#save_tab_cmd'
+          let arguments = [name, '', 'SaveTabSession']
         else
-          call xolox#session#save_cmd(name, '', 'SaveSession')
+          let function = 'xolox#session#save_cmd'
+          let arguments = [name, '', 'SaveSession']
+        endif
+        if xolox#misc#option#get('session_autosave_silent', 0)
+          " Silence informational messages perceived as noisy.
+          " https://github.com/xolox/vim-session/issues/120
+          silent call call(function, arguments)
+        else
+          call call(function, arguments)
         endif
       endif
     endif

doc/session.txt

@@ -28,15 +28,16 @@ Contents ~
   8. The |g:session_autoload| option
   9. The |g:session_autosave| option
   10. The |g:session_autosave_periodic| option
-  11. The |g:session_verbose_messages| option
-  12. The |g:session_default_to_last| option
-  13. The |g:session_persist_colors| option
-  14. The |g:session_persist_globals| option
-  15. The |g:session_restart_environment| option
-  16. The |g:session_command_aliases| option
-  17. The |g:session_menu| option
-  18. The |g:session_name_suggestion_function| option
-  19. The |g:loaded_session| option
+  11. The |g:session_autosave_silent| option
+  12. The |g:session_verbose_messages| option
+  13. The |g:session_default_to_last| option
+  14. The |g:session_persist_colors| option
+  15. The |g:session_persist_globals| option
+  16. The |g:session_restart_environment| option
+  17. The |g:session_command_aliases| option
+  18. The |g:session_menu| option
+  19. The |g:session_name_suggestion_function| option
+  20. The |g:loaded_session| option
  5. Compatibility with other plug-ins |session-compatibility-with-other-plug-ins|
  6. Known issues                                         |session-known-issues|
  7. Function reference                             |session-function-reference|
@@ -367,6 +368,12 @@ active sessions. The default is zero which disables the feature.
 Note that when the plug-in automatically saves a session (because you enabled
 this feature) the plug-in will not prompt for your permission.
 
+-------------------------------------------------------------------------------
+The *g:session_autosave_silent* option
+
+If you set this option to true (1) the messages normally emitted by automatic,
+periodic saving of active sessions are silenced.
+
 -------------------------------------------------------------------------------
 The *g:session_verbose_messages* option