Initialize the queue of the USART
Block some task for focusing develop on the shell
Merge branch 'free_rtos' of https://github.com/fboris/QuadrotorFlightControl

Conflicts:
	Program/Program_System/QCopterFC.c
Block the missing blocking-task related code
Port the command parser
Remove the system status variable
Complete the shell program with the command parser
Add *.swp into git ignore file
Add the header file "FreeRTOS.h" to avoid some warnings

*Also create command prototype "monitor"
Adjust the baudrate of USART3 to 57600
Create the interface of status monitor program
Add command "clear" and rename the RC signal
Move the KEY_ACTION enumeration to the header file
Add the internal command "quit" for the status monitor
Add the value of Space into the KEY_ACTION enumeration
Support command "resume" of the Status Monitor

*Complete the basic interface and architecture of the program
Add the command "ps" to the Shell
Support history record function
Update README.md
Support display copter attitudes and RC Messages to the status monitor