Add TitilliumWeb to project

- This action avoids access to fonts.google.com to fetch font used
  in documentation

CMakeLists.txt

@@ -90,6 +90,7 @@ if(DEFINED DOXYGEN_EXECUTABLE)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/doxygen/Doxyfile.in ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile @ONLY)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/doxygen/customdoxygen.css ${CMAKE_CURRENT_BINARY_DIR}/customdoxygen.css COPYONLY)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/doxygen/header.html ${CMAKE_CURRENT_BINARY_DIR}/header.html COPYONLY)
+    configure_file(${CMAKE_CURRENT_SOURCE_DIR}/doxygen/TitilliumWeb.woff2 ${CMAKE_CURRENT_BINARY_DIR}/doxygen/html/TitilliumWeb.woff2 COPYONLY)
 
     add_custom_target(doc
         ${DOXYGEN_EXECUTABLE} ${CMAKE_CURRENT_BINARY_DIR}/Doxyfile

doxygen/customdoxygen.css

@@ -1,3 +1,22 @@
+/* latin-ext */
+@font-face {
+  font-family: 'Titillium Web';
+  font-style: normal;
+  font-weight: 400;
+  font-display: swap;
+  src: local('Titillium Web Regular'), local('TitilliumWeb-Regular'), url(TitilliumWeb.woff2) format('woff2');
+  unicode-range: U+0100-024F, U+0259, U+1E00-1EFF, U+2020, U+20A0-20AB, U+20AD-20CF, U+2113, U+2C60-2C7F, U+A720-A7FF;
+}
+/* latin */
+@font-face {
+  font-family: 'Titillium Web';
+  font-style: normal;
+  font-weight: 400;
+  font-display: swap;
+  src: local('Titillium Web Regular'), local('TitilliumWeb-Regular'), url(TitilliumWeb.woff2) format('woff2');
+  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+2000-206F, U+2074, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
+}
+
 body, table, div, p, dl {
 	font: 400 16px/22px 'Titillium Web',sans-serif;
     color: #404244;

doxygen/header.html

@@ -8,7 +8,6 @@
 <meta name="viewport" content="width=device-width, initial-scale=1"/>
 <!--BEGIN PROJECT_NAME--><title>$projectname: $title</title><!--END PROJECT_NAME-->
 <!--BEGIN !PROJECT_NAME--><title>$title</title><!--END !PROJECT_NAME-->
-<link href="https://fonts.googleapis.com/css?family=Titillium+Web&display=swap" rel="stylesheet"> 
 <link href="$relpath^tabs.css" rel="stylesheet" type="text/css"/>
 <script type="text/javascript" src="$relpath^jquery.js"></script>
 <script type="text/javascript" src="$relpath^dynsections.js"></script>