SimplePostTool optimize does a redundant commit

At the end of SimplePostTool.execute() there is:

    if (commit)   commit();
    if (optimize) optimize();

Each of these calls involves a separate request to Solr. The thing is, an optimize internally commits, and so the logic should forgo committing is optimize is true.

And as an aside, I think the 1kb pipe() buffer on line 893 is too small; it should be around 8kb (8192) bytes which is the same value as BufferedInputStream's default.