add retry feature on broker side; modify QueryRunner inferface and tests
revert changes in pom file
change the way to use RetryQueryRunnerConfig
change the signature of run()
fix concurrency issue with the map; introduce new exception; add incomplete retry query runner test
fix header so it passes the entire context
delete an unused flag in QueryableIndexSegment
delete an unused flag in IncrementalIndexSegment
fix retry logic and change the default value of retry to 0
add more unit tests
change missigSegments to a static variable
change missigSegments to a static variable
add a test for retrying multiple times
change retry tests
revert changes to RetryQueryRunnerConfig
fixed merge conflicts
fix merge conflcts; change test files
Merge pull request #616 from metamx/jisoo

add retry feature on broker side; modify QueryRunner inferface and tests