handle exception
Merge branch 'develop' of https://github.com/FlightFinder/OAG_Schedule into develop
Merge pull request #23 from HaoranHuang/develop

added: stop searching if get N empty queries in a row. also add a check ...
added sorting
Merge branch 'develop' of https://github.com/FlightFinder/OAG_Schedule into develop
handles invalid input and return JSON message
flightSet class
Merge pull request #24 from snickers2029/develop

enable sorting
merge Controller.java
Merge branch 'develop' of https://github.com/FlightFinder/OAG_Schedule into develop
change HTTPResponse.java to match the new result format
Merge pull request #25 from samzhao88/develop

Handle exception more properly and change HTTPResponse to match the new result format from finder
the missing sorting line in former commit
Merge pull request #26 from snickers2029/develop

the missing sorting line in former commit
refactor the code in Controller.java and add a check for valid date input