Handle OAE URLs within Markdown syntax

Following up on issue #951, the relative link reformatting breaks if the OAE URL is already within a Markdown link.

So, for example, the following

    [Tenant](http://test.oae.com:8080/path/to/file)

Incorrectly results in the markdown code:

    [Tenant]([/path/to/file](/path/to/file))