Pipeline improvements (#964)

* Fix bug with toll-gate validation against master
* Change cppcheck to not attempt to validate headers directly and
  to run on the entire codebase in the pipeline.
* Support running Arduino test and examples build in parallel

.mystools/cppcheck/options.sh

@@ -5,6 +5,7 @@ OPTIONS="--quiet                                      \
 	--force                                             \
 	--enable=style,information                          \
 	-DCPPCHECK                                          \
+	--language=c++                                      \
 	--library=${LIBRARY:-avr}                           \
 	--platform="${TOOLCONFIG}"/${PLATFORM:-avr.xml}     \
  	--includes-file="${TOOLCONFIG}"/includes.cfg	      \