[yocto] eclipse-poky: Rootfs includes not in CDT

[Art Kaufmann]

Environment: Eclipse Neon 3 with the Yocto plug-in. Running on Fedora 24.

I've built the SDK and configured Eclipse and the plug-in. The Hello 
World autotools project builds, but, there's an issue. The CDT isn't 
aware of the include directories so its checker is flagging my files 
with missing includes errors. I *could* add ${SDKTARGETROOT}/usr/include 
(and the appropriate sub-directories) to my project's configuration, but 
I don't want to mess up the cross compiler which just uses the --rootfs 
option and finds everything that it needs. How do I configure this to 
get rid of the annoying errors? I like the help that the CDT provides 
before compilation.