Added missing doc and pylint's disables.
Added the `_wrap` method to the `Builder` class.

It wraps a SUDS object into a mantis4python wrapper.
Added the wrappers for ObjectRef's objects.

This include all the values that can be obtained througth
`enum` methods/SOAP calls.
Now the `enum` methods of `Connection` class returns this
wrappers instead of SUDS ObjectRef objects.