Historically $(OBJECTDIR) was created when Makefile.include is read. A
consequence is that combining "clean" with "all" (or any other build
target) results in an error because the clean removes the object
directory that is required to exist when building dependencies.
Creating $(OBJECTDIR) on-demand ensures it is present when needed.
Removed creation of $(OBJECTDIR) on initial read, and added an order-only
dependency forcing its creation all Makefile* rules where the target is
explicitly or implicitly in $(OBJECTDIR).
This is a general cleanup of things like code style issues and code structure of the STM32w port to make it more like the rest of Contiki is structured.
The added function let a process to make the system go
into deep sleep for maximum power saving.
The udp-ipv6-example shows how to use these new functions.
The symbol generation shell scripts cause CRLF issues on Windows/Cygwin again and again. Instead of fixing this yet again I opted to remove the symbol generation script at least for the "no symbols" scenario with two C source files to be copied.
