Merge lastest

1. Added a new class POSInfo to represent POS Info. It is used in method getPOSptn and method checkPOSInfo. Finished method getPOSptn and method checkPOSInfo.
2. Finished a part of doIt, and added two test cases.
3. Tested method checkWN systematically. Fixed bugs and added new test cases.
4. Issue 15 and Issue 16.
5. Added a few test cases of getNumber method.