Documentation: Update release notes and changelog

Signed-off-by: Roberto Rosario <roberto.rosario.gonzalez@gmail.com>

HISTORY.rst

@@ -105,7 +105,12 @@
   WORKFLOWS_IMAGE_CACHE_STORAGE_BACKEND_ARGUMENTS we added.
 - Added new list facet navigation menu. Used to provide facets
   to the setup menu items.
-
+- Add reusable, smart file caching system.
+- Use the new caching system to cache document version images,
+  document page images and transformes document page images.
+  The maximum size of the document cache is controlled
+  by the new DOCUMENTS_CACHE_MAXIMUM_SIZE setting.
+  This setting defaults to 500 megabytes.
 
 3.1.9 (2018-11-01)
 ==================

docs/releases/3.2.rst

@@ -1,7 +1,7 @@
-Version 3.2
+Version 4.0
 ===========
 
-Released: December XX, XX
+Released: XX XX, 2019
 
 
 Changes
@@ -77,6 +77,7 @@ Backward incompatible changes
 Bugs fixed or issues closed
 ---------------------------
 
+* :gitlab-issue:`395` Add support to limit the size of the cache.
 * :gitlab-issue:`487` gnupg1 Issue with Ubuntu 16.04 - Could not show/view documents
 * :gitlab-issue:`498` Can't scan subdirectories
 * :gitlab-issue:`522` Office 365 SMTP