Sketch KATResource API (and related classes) using ABCs
Responses to @ludwigschwardt comments in PR34
Rename KATCPResourceContainer and KATCPResourceClient as per @ludwigschwardt comments in PR34
Refactor normalize_strategy_parameters
Rework docstrings and fix __init__

Rework docstrings to conform to the NumPy standard and limit them to
80-character line lengths to improve appearance in interactive use.
Rename KATCPSensor._init to the more standard KATCPSensor.__init__.
It is the base class constructor after all.
Remove interface cruft

Unify the interface for blocking and asynchronous KATCP requests. Remove
premature abstractions.
Merge pull request #34 from ska-sa/katcpresource-abc

Sketch KATResource API (and related classes) using ABCs.

This introduces some base classes that underlie the high-level user interfaces in katcorelib
and the fake versions in kattelmod.