Add a global version number.

So the main() and About dialog can use it.

src/SeerUtl.cpp

@@ -3,6 +3,12 @@
 
 namespace Seer {
 
+    QString version () {
+
+        // Increment this with every release on GitHub.
+        return "1.0.5";
+    }
+
     QString filterEscapes (const QString& str) {
 
         QString tmp = str;