Setting Partial State in Assignment Mode Changes Independent State Values
Partially done - can now handle partial state input (not checked in yet)
Still need to 1) disallow state type change on input and 2) throw warning for coordinate system or epoch change
Reopening due to errors found by John Bez in GUI testing.
Reassigning to Steve for review of recent email exchange, and specification of appropriate error message.
CCB Decision: Testing that the validation catches disallowed settings in assignment mode is critical. P1 2012a