NMU 0.2.7-2.1 to eliminate epydoc and pychecker dependencies

This is my NMU for bug #933755 and bug #933758. It changes the build process so that epydoc and pychecker are no longer required build dependencies. It turns out that neither is strictly required in order for the package to build. The only functional difference is that the API documentation is not generated if epydoc is not available, which is exactly what we want in this case.

I know I haven't given you much notice on these bugs. I would normally wait a few weeks to give you a chance to respond. However, since this NMU makes only minimal functional changes to your package, I have decided to upload immediately rather than waiting. This lets me keep moving on the removal process for epydoc and pychecker, and at the same time allows me to close the two serious bugs against your package. You can merge these changes whenever it's convenient.