Fix up some comment issues spotted by rransom

src/common/compat.c

@@ -1481,7 +1481,12 @@ get_parent_directory(char *fname)
     fname += 2;
   }
 #endif
-  /* Now we want to remove the final character that */
+  /* Now we want to remove all path-separators at the end of the string,
+   * and to remove the end of the string starting with the path separator
+   * before the last non-path-separator.  In perl, this would be
+   *   s#[/]*$##; s#/[^/]*$##;
+   * on a unixy platform.
+   */
   cp = fname + strlen(fname);
   at_end = 1;
   while (--cp > fname) {

src/common/util.c

@@ -1664,10 +1664,10 @@ file_status(const char *fname)
     return FN_ERROR;
 }
 
-/** Check whether dirname exists and is private.  If yes return 0.  If
- * it does not exist, and check&CPD_CREATE is set, try to create it
+/** Check whether <b>dirname</b> exists and is private.  If yes return 0.  If
+ * it does not exist, and <b>check</b>&CPD_CREATE is set, try to create it
  * and return 0 on success. If it does not exist, and
- * check&CPD_CHECK, and we think we can create it, return 0.  Else
+ * <b>check</b>&CPD_CHECK, and we think we can create it, return 0.  Else
  * return -1.  If CPD_GROUP_OK is set, then it's okay if the directory
  * is group-readable, but in all cases we create the directory mode 0700.
  * If CPD_CHECK_MODE_ONLY is set, then we don't alter the directory permissions