first commit, working UT
Merge branch 'master' into query-prioritization
cleanup
Merge branch 'master' into query-prioritization
fix according to code review
more code review fixes
Merge pull request #156 from metamx/query-prioritization

Query prioritization
[maven-release-plugin] prepare release druid-0.5.0
[maven-release-plugin] prepare for next development iteration
fix pushing down too many properties
[maven-release-plugin] prepare release druid-0.5.1
[maven-release-plugin] prepare for next development iteration
Fix getImplicitLockInterval check
[maven-release-plugin] prepare release druid-0.5.2
[maven-release-plugin] prepare for next development iteration
Update RealtimePlumberSchool.java

There was an issue if you restart realtime node and merged dir is still there it will throw exceptions. To tackle this issue a check has been added. So now only persisted dir/files will be read and anything from "merged" will be avoided.
enable snappy compression for memcached results
swap out snappy for LZ4
Merge pull request #155 from metamx/snappy-cache-compression

enable cache compression for memcached
add delegating executor service and fix bug with query priortization