Initial commit, basic function of BKTree
Merge branch 'develop' into final_feature_BKTree
Merge branch 'develop' into final_feature_Spell_Check_BKTree
Implemented spell correction with bug fixed...

1. Implement spell correction…
2. Fix some bugs in BK Tree…
Merge branch 'develop' into final_feature_Spell_Check_BKTree
Implement query correction...

1. In the web page, when a user is typing a query, the page will send
the unfinished query to the server with a certain intervals. a). If the
last term of the query exists in the dictionary comes from the index,
then several expanded query will be sent back to the pages as
suggestions. b). If the last term does not exist, a spell check will be
ran and several corrected query will be sent back to the page….
Added a evaluator for spell check...
Improved BKTree...
Add misspell data to improve accuracy :)
Complete the evaluation for BKTree spellcheck..
Improved the spell check...
Add throw exception...
Add a new dictionary...
Add reference...
Merge branch 'final_feature_Spell_Check_BKTree' into develop