fix cardinality aggregator serde
move thanks page to main site
RemoteTaskRunner should respect worker version changes (fixes #787).
Merge pull request #788 from metamx/rtr-worker-disablement

RemoteTaskRunner should respect worker version changes (fixes #787).
update bytebuffer collections dep to fix issue with empty spatial concise sets
Merge branch 'master' of github.com:metamx/druid
prepare for next release
[maven-release-plugin] prepare release druid-0.6.159
[maven-release-plugin] prepare for next development iteration
add a best practices doc
simplify test for approx histogram
remove unused test code
fix groupBy ordering casing bug
Merge pull request #790 from metamx/fix-groupby-order-casing

fix casing issue when specifying ordering dimension in groupBy
Updated druid-api version to always sort dimension names, these tests needed fixing