Fix the bug #42 - replace the heap_2.c to heap_4.c

*heap_4.c implement a better algorithm about the memory management
Merge pull request #43 from shengwen1997/master

Replace heap_2.c to heap_4.c
Move SYSTEM_STATUS to sys_manager.h
Fix casting warning
Support hotkey "Ctrl + C" to the linenoise
Fix typo
Update README.md
Support linenoise autocomplete to the status monitor
Merge branch 'master' of github.com:zxc2694/QuadrotorFlightControl into zxc2694-master

Conflicts:
	Program/Program_System/QCopterFC.c
Merge pull request #45 from shengwen1997/master

Support some linenoise functions
Put shell related files together into the "shell" directory
Create the stdlib directory for restoring the C Std lib related files
Let the status monitor delay for 250ms after refresh the screen
Merge branch 'master' of github.com:shengwen1997/QuadrotorFlightControl into shengwen1997-master