platform: stm32f1: simplify the annotation of no platform-specific
Makefile: rename "common" to "platform-common" for consistency
Merge pull request #104 from slpbaby/stm32p103-fixed

platform: stm32p103: add mem0 start address
semihost: add semihost library
platform: add semihosting enable option for stm32p103
gitignore: ignore mylog
travis: update default config for stm32p103
makefile: add qemu command
semihosting: add weak alias for semihost_puts