Added valgrind memory leak tests for backend. Fixed some minor leaks and file descriptor closes.

lib/src/clixon_file.c

@@ -160,9 +160,11 @@ clicon_file_dirent(const char     *dir,
 
    qsort((void *)new, nent, sizeof(*new), clicon_file_dirent_sort);
    *ent = new;
+   new = NULL;
    retval = nent;
-
 quit:
+   if (new)
+       free(new);
    if (dirp)
        closedir(dirp);
    if (regexp)

lib/src/clixon_log.c

@@ -103,6 +103,7 @@ clicon_log_exit(void)
 {
     if (_logfile)
 	fclose(_logfile);
+    closelog(); /* optional */
     return 0;
 }
 

lib/src/clixon_yang.c

@@ -2556,6 +2556,8 @@ yang_spec_load_dir(clicon_handle h,
 	goto done;
     retval = 0;
   done:
+    if (dp)
+	free(dp);
     if (base)
 	free(base);
     return retval;