Add changes file for Qt 5.12.1

+ 9fcf2a90 Bump version
+ 92ae7296 Add changes file for Qt 5.11.3
+ 62ee0320 Clean up windows qmake scopes
+ d369df14 Doc: Add missing closing parenthesis in snippet
+ 7844b913 Fix compilation with gcc 4.8
+ 0eb8ff63 Only include the ssl example and test if the OpenSSL feature is available
+ 8eeb2154 SSL Examples: Explicitly state SSL requirement
+ 76819c03 Convert QNX backend to use shared pointers
+ b513d17f Clang warning cleanup in qnx backend
+ b89cee78 QVariant is also a standalone type and we must treated accordingly
+ ab6e0edd

 Bump version

Change-Id: I5ce74358fa5e1324f1ecdc3a0e28ae411b19db8f
Reviewed-by: Michael Brasser <michael.brasser@live.com>

dist/changes-5.12.1

+Qt 5.12.1 is a bug-fix release. It maintains both forward and backward
+compatibility (source and binary) with Qt 5.12.0.
+
+For more details, refer to the online documentation included in this
+distribution. The documentation is also available online:
+
+http://doc.qt.io/qt-5/index.html
+
+Note: Tech Preview modules are able to change APIs to refine or enhance the
+module's functionality.  Thus Qt's binary compatibility quarantees aren't
+applicable.  Code switching to 5.12 (when Remote Objects "graduated" from
+Tech Preview) from earlier versions of Qt Remote Objects will need to be
+recompiled.
+
+Some of the changes listed in this file include issue tracking numbers
+corresponding to tasks in the Qt Bug Tracker:
+
+https://bugreports.qt.io/
+
+Each of these identifiers can be entered in the bug tracker to obtain more
+information about a particular change.
+
+****************************************************************************
+*                            Qt 5.12.1 Changes                             *
+****************************************************************************
+ - General
+   * [QTBUG-72064] QVariant is also a standalone type and we must treat it
+     accordingly
+   * Convert QNX backend to use shared pointers
+   * Various code cleanup