- consider all ranks instead of considering current ranks in the current stream

- refined interaction btw legendview and streamview/historyview

- added adjustable statistics:
        min
        max
        mean
        std
        skewness
        kurtosis
        cumulative delta
- added adjustable comparison size  
- aggregated stats will be provided from PS

- added adjustable statistic types for y axis
- added adjustable comparison size for x axis
- minor updates, i.e., ajax request, constant.js, HTML/CSS

- added window size (number of frames) attribute instead of end
- backend query can be split into static (specified) and dynamic (the latest)

- added prev next buttons for the static mode in the historyview
- refined component size
- added constant values for historyview

- dynamic mode visualizes the latest frames in the selected ranks
- static mode visualizes overall frame distribution from the first via interval query
- related code updates in the streamview and data.js

- Jest: unittest module for frontend application based on node.js
- install Jest throough npm & run shell the script for the frontend module

- existing data object has mixed functionalities for model, view and controller
- currently splitting Model functionalities from the data object

- added jest configuration
- added basic test for data.js --> to be split into  Model and Controller

- removed tests for deprecated methods
- updated test for adding frames to buffer

- added test data for checking number of ranks

- added Controller as part of MVC design pattern
- minor refinement for Model, views, and index.html

- as MVC pattern is applied, subsequent modification was updated in both Streamview and Legendview

- update config class

- refined minor bug

- refined control panel for historyview
- refined scatter view layout

- added latest frame id so that the dynamic mode can get the frame interval
- rotated x-axis texts to avoid overlapping
- refined overall layout
- debug navigating in the static mode

- debugged setting comparison size
- adjusted rendering interval

- debugged layout adjustment

- refined test case for the update() api in Model
- added test case for the data processing for StreamView

-  data processing for the StreamView is moved to Model

- added test case for HistoryView
- modified codes for supporting MVC design

- added test data for StreamView and HistoryView

- backend: re-route to the prev constructing algorithm
- frontend: apply new MCV design