* commit '14ff147':
  Squashed 'features/frameworks/mbed-trace/' changes from 7a1bd34..0a4f6be

* commit '1374a5e':
  Squashed 'features/frameworks/mbed-trace/' changes from 9eaf0d1..7a1bd34

Nanostack related files moved under 'feature/nanostack'
Common libraries moved to 'features/frameworks'

Allow FEATURE_COMMON_PAL still to be defined in the build so
that we don't break any builds.