new demo paper
more edits
Memcache changes
add router node
add tests
clean up failure scenarios
updated task ID definition
Add headers
merge changes from master
extend context to use map string object instead of map string string
Merge branch 'master' of github.com:metamx/druid into better-context
Merge branch 'master' into demo-paper
more updates
more edits
Update index.md

Fixed a few typos and grammatical issues.
replace png with pdf graphics
include final license and DOI link
final sigmod version
more logging at initialization
Merge branch 'master' of github.com:metamx/druid