Renamed 'halt' to 'hold' to make it more reasonable
support system time in ms unit
Use ms to calcuate mission(wp read and write) timeout
200ms is default value in qgroundcontrol
Merge branch 'add_OS_for_test' of https://github.com/ming6842/firmware into merge_ming

Conflicts:
	program/controller/navigation.c
Merge pull request #133 from moon-bear/rename_hold

Rename hold
Port old printf as well as basic convert function
retarget printf to printf_base, port itoa,ltoa,ftoa...
Fix wrong header guard definition
Fix some warning
Let compile and link separately
But cannot find reset handler
warning: cannot find entry symbol Reset_Handler; defaulting to 0000000008000000
Support openocd to flash program
Merge pull request #139 from moon-bear/support_openocd

Support openocd to flash program
Merge pull request #135 from moon-bear/fix_printf

fix printf problem in #130
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