tests: update template and add pids

Generalised the library API tests and created a common
test-runner. Instead of copy and pasting the same code in
each time.

First cut of pids API test, for _new so far.

include/tests.h

@@ -2,9 +2,26 @@
 #ifndef PROCPS_NG_TESTS_H
 #define PROCPS_NG_TESTS_H
 
-struct test_func {
-    int (*func)(void *data);
-    char *name;
-};
+typedef int (*TestFunction)(void *data);
 
+char *testname;
+
+
+static inline int run_tests(TestFunction *list, void *data)
+{
+    int i;
+    TestFunction current;
+
+    for (i=0; list[i] != NULL; i++) {
+        testname = NULL;
+        current = list[i];
+        if (!current(data)) {
+            fprintf(stderr, "FAIL: %s\n", testname);
+            return EXIT_FAILURE;
+        } else {
+            fprintf(stderr, "PASS: %s\n", testname);
+        }
+    }
+    return EXIT_SUCCESS;
+}
 #endif