Add new functions on data view page

Add two functions:

1. can manually set the data sensing range.
2. make x axis meaningful, i.e. the sampling timestamp. (10Hz)

First Version to verify the prototype

Functions,
Link to Rfduino BLE circuit, show the current readers, and draw a dynamic line chart for exploring the sensor's property.
But,
there is no local database, only export the data by using other apps, like email clients.