[fix] nucleo target - gcc arm removal from targets.py
Merge pull request #199 from 0xc0170/dev_nucleo_gcc_removal

[fix] nucleo targets - gcc arm removal from targets.py
Remove F401RE from IAR exporter.

http://mbed.org/users/mbed_official/code/mbed/issues/12
Update MBED_LIBRARY_VERSION to latest revision
NORDIC can now reset using serial break
Merge branch 'master' of https://github.com/mbedmicro/mbed