1. modified code in recv_callback, which allows user to set the fullscale magnetometer and report period
2. modified the sample javascript code for uplink and downlink data parser on the cloud
1. modified the HTS221: removed magic numbers, added a sensor_tempnhumi_t struct to accommodate temperature and humidity data
2. added .h and .c files for LIS3MDL magnetic sensor
3. added .h and .c files for LPS22HB pressure sensor
3. added IAR (EWARM) project for lorawan example
4. added bsp.c and bsp.h to manager the sensors