add note to buckets.md
add notes in buckets and bucket types docs
some notes
still need more info on sibling explosion
rough draft
remove unnecessary 'very'
clean up usage section
add to global nav
merge with 2.0.0
Rewrite DVVs vs. Vector Clocks section.

This should now correctly describe the distinction between VCs and
DVVs. I have no idea what it was trying to describe previously.
Forgot to finish that sentence at the end of the vs. section.
remove link from nav
Merge pull request #1070 from basho/lp/dvv_enabled

Ready: Document dvv_enabled