Generate version header when configuring project

The basic idea is we create a version header template at
"src/base/version.h.in" and the build systems are expected to replace
strings that are enclosed with @ symbols and generate
"src/base/version.h" for other source files to consume/include.

src/app/main.cpp

@@ -78,6 +78,7 @@ Q_IMPORT_PLUGIN(QICOPlugin)
 
 #include "base/preferences.h"
 #include "base/profile.h"
+#include "base/version.h"
 #include "application.h"
 #include "cmdoptions.h"
 #include "upgrade.h"