New options for downloads embedded in blog posts: sorting and limit number of files shown in blog stream.
Added explanation of new options to README.md, and optimized the stream_limit option.
Updated README.md
Update wp-downloadmanager.php

`id` and `category` are now also `0` instead of `'0'`.
Merge pull request #1 from ksze/master

New options for downloads embedded in blog posts: sorting and limit number of files listed in blog stream