updated the docs for streaming-custom-receivers

tmp checkin - multiple kinesis workers are working
added docs, added record handler
sync'd java-friendly version with scala version
started tests
updated build and example scripts to be extras/spark-kinesis-asl aware
more updates to docs and build
added windows run-kinesis-example.cmd
added param for kinesis checkpoint interval
updated documentation
updated docs
fixed logging, renamed converter to serializer
cleaned up the retry method
added tests and updated documentation
udpated documentation
updated docs, fixed bug with union of multiple streams
updated docs
updated docs
cleaned up CheckpointState, added more tests, added more docs
more doc updates
more updates
more updates