enable CSV Reader to ignore invalid lines like an empty line at the end and comments - FLINK-1208

Corresponding to issue FLINK-1208:
enable CSV Reader to ignore invalid lines like an empty line at the end, multiple header lines or comments without throwing an exception
There is checking for input correctness in GenericCsvInputFormat.parseRecord() and the exception will be thrown their so we will never come to this line:

14/11/25 09:46:36 INFO taskmanager.TaskManager: Shutting down TaskManager
Exception in thread "main" org.apache.flink.runtime.client.JobExecutionException: org.apache.flink.api.common.io.ParseException: Row too short: invalid line
	at org.apache.flink.api.common.io.GenericCsvInputFormat.parseRecord(GenericCsvInputFormat.java:284)
	at org.apache.flink.api.java.io.CsvInputFormat.readRecord(CsvInputFormat.java:235)
	at org.apache.flink.api.java.io.CsvInputFormat.readRecord(CsvInputFormat.java:1)
	at org.apache.flink.api.common.io.DelimitedInputFormat.nextRecord(DelimitedInputFormat.java:489)
	at org.apache.flink.api.java.io.CsvInputFormat.nextRecord(CsvInputFormat.java:203)
	at org.apache.flink.api.java.io.CsvInputFormat.nextRecord(CsvInputFormat.java:1)
	at org.apache.flink.runtime.operators.DataSourceTask.invoke(DataSourceTask.java:195)
	at org.apache.flink.runtime.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:245)
	at java.lang.Thread.run(Thread.java:745)