Issue 037: incomplete resolution

[Alastair Green <alastair.green@choreology.com>]

Issue 037 was resolved by agreeing that any late registration will 
receive Cannot Register Participant in response.

However, the CV state table shows Invalid State being sent when late 
(post-prepare wave) registrations occur.

Proposal: to ask the editors to amend the cells in the CV Register row 
that show Invalid State and replace with CannotRegisterParticipant.

Secondary, stylistic issue. Do we name faults in the form XYZ or X Y Z? 
Example: "CannotRegisterParticipant" or "Cannot Register Participant".

Resolutions of 037 and of 050 use different forms. Suggest we always use 
space delimited form, as this is the pattern elsewhere.

Alastair