Add test or sample app using OsCommandBatchlet

Add a test or sample app using org.jberet.support.io.OsCommandBatchlet to perform some OS command operations.

For example,

• split a large text files into multiple smaller files by number of lines, to prepare for partitioned step execution;

• sort large text files;

• merge multiple text files;

• cut text files by columns;

• generate pdf report files by running acrobat command line tools;

• any other custom shell scripts or Windows bat scripts.