Allow non-ASCII (UTF-8) characters in user first and last name in user profile

We do this by forcing a UTF-8 byte order marker in the profile.xml file.
We also add processing instructions that specify UTF-8, although it seems the BOM is itself sufficient.

Htmldocs/release_notes.html

@@ -17,6 +17,7 @@
     <ul>
       <li>[fix] Correct calculation of average leak rate on Welcome page.</li>
       <li>[fix] Correct installation of non-English Release Notes on Windows.</li>
+      <li>[fix] User first and last name in Profile window may now have non-ASCII (UTF-8) characters.</li>
     </ul>
     <p>
     <b>Changes and fixes in OSCAR v1.2.0</b>

oscar/SleepLib/preferences.cpp

@@ -335,6 +335,9 @@ bool Preferences::Save(QString filename)
 
     QDomDocument doc(p_name);
 
+    QDomProcessingInstruction pi = doc.createProcessingInstruction("xml", "version=\"1.0\" encoding=\"UTF-8\"");
+    doc.appendChild(pi);
+
     QDomElement droot = doc.createElement(STR_AppName);
     doc.appendChild(droot);
 
@@ -368,6 +371,8 @@ bool Preferences::Save(QString filename)
     }
 
     QTextStream ts(&file);
+    ts.setCodec("UTF-8");
+    ts.setGenerateByteOrderMark(true);
     ts << doc.toString();
     file.close();