Properties module can now take multiple properties files
refactor examples to use global runtime
Merge branch 'master' into new-init

Conflicts:
	examples/config/historical/runtime.properties
	examples/config/overlord/runtime.properties
	examples/config/realtime/runtime.properties
add header
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
initial support for LZ4 compression