Implement Operator to pick up files from disk and put them into the
storage
Implement SequentialIntGenerator as RangeIntGenerator is not thread-safe
and has other problem. Also minor fixes an remov debug output from
FileWriter
Sample Config for the filewirter, and a txt file explaining how it
should be used.
Merge branch 'filewriter'

Conflicts:
	dev/cosbench-driver/src/com/intel/cosbench/driver/operator/FileWriter.java
	dev/cosbench-driver/src/com/intel/cosbench/driver/util/FilePicker.java