Display docstrings in RESTAPI documentation

Hi,

according to the cheetah template for the RESTAPI documentation, docstrings of exposed methods should be displayed in the auto-generated documentation page. Currently that feature is not working properly, because _addMethod contains a wrapper function around the original method, thus the docstrings of the original method are lost. One can re-enable the feature by using the wraps decorator from functools. DBS was ask to improve the documentation in https://svnweb.cern.ch/trac/CMSDMWM/ticket/4009 and we would to use that feature of WebTools.

Could you review and merge that patch, please?

Thanks,
Manuel