Dominates should not take timestamp into account.

Ensure that dominates does not take the timestamp into account; two
concurrent puts happening one second apart should not be considered
related.
Update EQC model to reflect change in `dominates`
Add explanatory comment to `dominates` for posterity
Remove redundant test

This test duplicates the behavior of `vclock_qc`
Update comments / docs on dominates for accuracy
Merge pull request #510 from basho/bugfix/csm/dominates

Dominates should take timestamp into account.