libprocps version test and documentation

test binary and man page for the version part of libprocps.
It's a simple start, but it's a start!

include/tests.h

@@ -0,0 +1,10 @@
+
+#ifndef PROCPS_NG_TESTS_H
+#define PROCPS_NG_TESTS_H
+
+struct test_func {
+    int (*func)(void *data);
+    char *name;
+};
+
+#endif