using timer object to measure runtime
some changes in inheritance for SortLists
use new ListFromFile class to get PiList
Merge branch 'penn-dev' into doc
changed inheritance for Sorters
Cleanup sort_lists

- some refactoring
- added javadoc
Cleanup sorters

- some refactoring
- added javadoc
Cleanup timer

- some refactoring
- added javadoc
Cleanup test

- some refactoring
- added javadoc
Merge pull request #9 from Pennham/penn-dev

Penn dev