Let compile and link separately
But cannot find reset handler
warning: cannot find entry symbol Reset_Handler; defaulting to 0000000008000000
Set PC9 as debug toggle port
[Flight test]Test only with the flight control task
Fix the "PE9" Timer not initialized issue
Fix 'no reset handler issue', not test yet
This commit have fixed the most of part of linking error.
1)`---nostartfiles` option conflict with `CFLAGS_NEW_LIB_NANO`
2)only link mathlib, no standard lib(we already have used newlib-nano)
3)the no reset hanlder issue is dangerous. Actually, I found we only link one object file to elf. I didn't set the variable of objs correctly. This warning implied linker could not find any implementation part of reset handler.
Merge branch 'os_dev' into makefile_improve

Conflicts:
	program/Makefile
Delete useless splash
Support openocd to flash program
Merge pull request #142 from moon-bear/makefile_improve

Makefile improve
Merge pull request #140 from moon-bear/flight_control_task_debug

Debug port for testing the flight control task
Remove the PC9 timer initialization
Merge branch 'os_dev' into os_shengwen_flight