Clean input operators in lib

1. Split the com.datatorrent.lib.io to 
 com.datatorrent.lib.io.fs
 com.datatorrent.lib.io.console
 com.datatorrent.lib.io.http
 com.datatorrent.lib.io.websocket
 com.datatorrent.lib.io.smtp
 com.datatorrent.lib.io.jms

2 remove ActiveMQInputOperator which is duplicate to AbstractActiveMQInputOperator

3 Add a HdfsTestFileInputOperator( and unit test HdfsTestFileInputOperatorTest) which is default implementation and template to AbstractHDFSInputOperator

4 Add ActiveMQSinglePortStringInputOperatorTest to test ActiveMQSinglePortStringInputOperator