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
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
Merge branch 'os_dev' into makefile_improve

Conflicts:
	program/Makefile
Delete useless splash