dumpdir now supports exclusions

Job-configuration.md

@@ -112,6 +112,11 @@ test will fail anyway.
   purposes) recursively, with a limit on the total size of the destination
   directory. Files that do not fit into the limit are skipped and
   placeholders (with names like `original_file_name.skipped`) are created.
+  Calling command is `dumpdir` and require at least three arguments:
+	- source path which should be dumped
+	- destination path where source directory should be dumped
+	- size limit in kilobytes on the whole source folder
+	- fourth and further arguments are exclusions, paths which should be excluded from copying
 - **Truncate task** cuts off data from the end of a file so that it fits a limit
   supplied as an argument. This is done in place, using
   [boost::filesystem::resize_file](http://www.boost.org/doc/libs/1_60_0/libs/filesystem/doc/reference.html#resize_file).