Export WholeBodyToolbox.slx as a 2016B SLX file (#221)

* Export WholeBodyToolbox.slx as a 2016B SLX file

Furthermore, modify the matlab/export_library.m file to export that
file as 2016B.

Fix #219

Author: traversaro

CHANGELOG.md

@@ -5,11 +5,15 @@ The format of this document is based on [Keep a Changelog](https://keepachangelo
 
 ## [Unreleased]
 
-## [5.4.1] - 2021-05-xx
+## [5.4.1] - 2021-05-28
+
+### Changed
+- The `WBToolboxLibrary.slx` file is now encoded in R2016b slx format, so at least MATLAB R2016b is required to use it.
 
 ### Fixed 
 - Fixed bug that caused Simulink models that used OSQP block to hang indefinitely in "Initializing" or "Compiling" phase (https://github.com/robotology/wb-toolbox/pull/220).
 - Disable verbose output option in OSQP block (https://github.com/robotology/wb-toolbox/pull/220).
+- Fixed problem introduced in 5.4.0 that prevented the `WholeBodyToolbox` library to appear correctly in the Simulink library browser on some MATLAB versions and on some Operating Systems (spotted on MATLAB R2020b with Ubuntu 20.04) (https://github.com/robotology/wb-toolbox/issues/219, https://github.com/robotology/wb-toolbox/pull/220).
 
 ## [5.4.0] - 2021-05-24
 

CMakeLists.txt

@@ -3,7 +3,7 @@
 # GNU Lesser General Public License v2.1 or any later version.
 
 cmake_minimum_required(VERSION 3.5)
-project(WB-Toolbox LANGUAGES CXX VERSION 5.4.0)
+project(WB-Toolbox LANGUAGES CXX VERSION 5.4.1)
 
 if(WBT_BUILD_DOCS)
     add_subdirectory(doc)

matlab/export_library.m

@@ -2,12 +2,7 @@
 % This software may be modified and distributed under the terms of the
 % GNU Lesser General Public License v2.1 or any later version.
 
-fprintf('\nWhole Body toolbox exporting library to multiple versions\n');
-
-if (verLessThan('matlab', '8.4'))
-    error('This script should be launched with a MATLAB version >= than 2014b');
-    quit;
-end
+fprintf('\nWhole Body toolbox exporting library to old Simulink version\n');
 
 addpath(genpath('library'));
 libraryName = 'WBToolboxLibrary_repository';
@@ -26,8 +21,8 @@
 
   % Export the library. It must be in slx otherwise it will not show up in
   % the Simulink Library browser.
-  fprintf('\nExporting for 2014b\n');
-  save_system(libraryName, 'WBToolboxLibrary', 'ExportToVersion', 'R2014B_SLX');
+  fprintf('\nExporting for 2016b\n');
+  save_system(libraryName, 'WBToolboxLibrary', 'ExportToVersion', 'R2016B_SLX');
   movefile('WBToolboxLibrary.slx', 'library/exported/WBToolboxLibrary.slx');
 
   % Unload the library