Fix build against cstruct.0.8.0, which doesn't like duplicate field names

(not an unreasonable requirement imho)

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Update CHANGES

Signed-off-by: David Scott <dave.scott@eu.citrix.com>
Merge pull request #6 from djs55/fix-cstruct8

Fix build against cstruct.0.8.0