Merge lastest

* Added a new class POS, to define all the POS tags. This would make it easier to maintain.
* Added a FAQ in the wiki.
* Added a Configuration class to hold all configurations. Added a Utility class to hold all utilities.
* Added log4j and used it to trace/debug code. Changed some existing print msgs to log4j msg.
* Added a readme.md file.
* Moved all methods used to update tables to DataHolder class. Added helpers, test cases and tested most of them (methods addModifier(), updateUnknownWord(), updatePOS(), resolveConflit(), discountPOS(), getParentSentenceTag(), tagSentWithMT(), tagSentWithMT(), changePOS()). Fixed any bugs.
* Added a family of methods in DataHolder class to add entries of any data holders
* Added test cases, tested, and fixed bugs of methods posBySuffix(), containSuffix().
* Added some test cases to methods markByPattern(), markupIgnore(), checkWN(), and tested them.
* Added a new utility equalsWithNull() in StringUtility class. 
* Added a family of methods in the DataHolder class to output all content in one specified holder.
* Added a helper of method discover(), which is isMarked().
* Miscellaneous bugs fixing and modifications.