1. revoke the inline declaration for easy compilation (maybe inline again after I find out how to compile inline functions easily)
2. add .gitignore to in sub-directory to ignore the exectutable files.
3. write a short test_pprz_msg.cpp to test the usage of the pprz_msg.h
1. Fix the bugs of pprz_read_byte() series.
2. Write a simple test_pprt_msg.cpp functions
1. add function prototypes of pprz_msg get_pprz_msg() and void set_pprz_msg() in XBEE_msg for compatible usage of XBEE_msg and pprz_msg