Memcache changes
add router node
add tests
clean up failure scenarios
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
fix typos
update document class for sigmod
update makefile to create sigmod zip file
add keywords
copyright placeholder
updated pdf
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