Problem: When trying to access a managed file from a job configuration the link being provided is invalid.

Example: Get http://my.jenkins/job/myverynicejob/configfiles/show?id=scriptiwant but need http://my.jenkins/configfiles/show?id=scriptiwant

Reason: in DetailLinkDescription the method getDetailsLink uses context.getUrl() but should use a function providing the base URL of Jenkins and not the relative location. (I don't know the correct function, else I could have provided a pull request.)