Documentation for defer.gatherDeferreds and defer.DeferredList is not clear

[cyli]

 The documentation for DeferredList makes mention of the DeferredList changing what callbacks/errbacks on the individual Deferreds can see, an elaboration as to why would be helpful.

The consumeErrors parameter's description is also confusingly worded, with alternating usage of the terms "included Deferreds" and "individual Deferreds". Some examples (or given the different parameters DeferredList takes, perhaps a table) would help readers understand the behaviour better.

 The documentation for gatherResults has the same confusing wording. In addition, it does not mention that gatherResults is implemented with DeferredList with fireOnFirstError set to True, and thus that the Failure that is returned will be a FirstError.