Handle incompatible record in Riak 1.4.0.

Return badrpc calls with an incompatible message when unable to
determine which versions of nodes are communicating in a mixed-
version cluster.

Switch to macros for record definitions.

Also, suppress information in the UI when detecting this incompatibility
to prevent from the display of NaN values.

Conflicts:
	priv/admin/js/core.js
	priv/admin/js/generated/templates.js
	src/riak_control_session.erl
	src/riak_control_wm_cluster.erl
Resolve incorrect capability negotation order.
Fix bad pattern match.
Add overall status.

Return an overall status that can be used to monitor cluster
transitions.
Merge pull request #126 from basho/csm-riak-control-record-fix

Handle incompatible record in Riak 1.4.0.