v0.3.0 release

Change log:

• Ignore test folder & nslist from mbed classic build
• Merge pull request #40 from ARMmbed/prepare-for-mbed-trace
• Added cmd_vprintf (#41)
• added mutex wait/release callbacks for thread safety (#42)
• add MBED_CONF_MBED_TRACE_ENABLE trace enable flag support (#43)
• Update README.md (#46)

v0.2.0 release

Several small fixes and tweaks

• use public mbed-trace dependency (latest for now is v1.1.2)
• update ns_list:ns_types
• fix tests with GCC 5.3.0
• fix compiling with armcc 5.06
• clean some compile warnings
• license update (mbed partner license)

v0.1.0

Initial release version.