This commit fixes the module-level docstrings for the tests and helper
modules in qa. Many of these tests were uncommented previously - this
commit ensures that every test case has at least a minimum level of
commenting.
Port over https://github.com/chronokings/huntercoin/pull/19 from
Huntercoin: This implements a new RPC command "getchaintips" that can be
used to find all currently active chain heads. This is similar to the
-printblocktree startup option, but it can be used without restarting
just via the RPC interface on a running daemon.