Increase maxBuffer size when running phpDocumentor

[timmd909]

This is a band-aid until more control over phpDocumentor's output can be implemented. When processing a large number of files that have a lot of missing documentation, the buffer fills up pretty quickly. This will increase the buffer to 1 MiB, which was enough to handle over 30,000 lines of Argument $XXX is missing from the Docblock of \foobar() and No summary for function \foobar().