Merge pull request #6 from samorris/master

ZSK Rollover Changes - 9 May 2014
Updated state description section to emphasise rollover states

Originally the section described key states.  This change changes
the text to make it rollover-centric rather than key-centric.
Update author contact details
Add Matthijs Mekking as co-author
Updated location of RFC reference XML files
Renamed KSK "Double-Signature" rollover to "Double-KSK"

As agreed at the teleconference between the authors on 10 June 2014.
Remove rollover summary table

As agreed at the teleconference between the authors on 10 June 2014.
The summary table only listed the order the different records were
published and did not really contribute to the understanding of the
document.
update definitions
Merge pull request #7 from matje/master

update definitions
update changelog
Merge pull request #8 from matje/master

update changelog
rm double word: section
suggestion for timeline diagram ZSK Pre-Publish
fix organization
W
and/or -> or
update key state definitions
some more changes to key state definitions
revert-03 and adjust ZSK Pre-Publication Method
revert ZSK Double-Signature Method diagram