Fix version and commit display

Made version and commit variables static, and local to the version
display function. Previously, they would be globals, and as such would
collide with those from linked shared libraries. Now, all project types
will have them local.

tpl/version.cpp

@@ -1,9 +1,9 @@
 #include "version.hpp"
-#include "version.inc"
-#include "commit.inc"
 #include <sstream>
 
 std::string {PROJECT}_version() {
+#include "version.inc"
+#include "commit.inc"
     std::ostringstream oss;
     oss << "{PROJECT} version " << version;
 #ifdef DEBUG