* Bug 27823 - Re-enable functionality of --uploads option of importDump.php; introduc...

* Bug 27823 - Re-enable functionality of --uploads option of importDump.php; introduce --namespaces filter option for importDump.php

Patch from Dmitriy Sintsov of which he writes:

    I needed to selectively import files from URL's defined in
    previousely made XML dump. This worked fine in 1.15, but to my
    surprise wasn't working with 1.17, producing an error. I've
    partially fixed upload code (including supplying of original User
    instance for local upload) and introduced new option to
    selectively import only the listed namespaces in importDump.php
    command line.