org.eclipse.jdt.core.prefs: Why is it checked in?

[Rod Widdowson]

I admit that I spent only as much time with system administration as is commensurate with keeping my system secure

So as a matter of course I systematically keep tools I use to get work done on the oldest support version. 

As of not so very long ago, git is spending a lot of time telling me that "org.eclipse.jdt.core.prefs" (in every folder in every
project) is out of date.  This might be because I updated from Java7 just recently, or it might be that my laptop is running the
latest eclipse (although I get the same error when I plug my work disk into my desktop running eclipse "Oxygen (4.7.3a)"

The differences are quite interesting:

	-org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.7
	+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8

	-org.eclipse.jdt.core.compiler.compliance=1.7
	+org.eclipse.jdt.core.compiler.compliance=1.8

	-org.eclipse.jdt.core.compiler.source=1.7
	+org.eclipse.jdt.core.compiler.source=1.8

So I guess I have 3 question:

 - Am I the only one getting this and if so what did I do wrong?
 - Given that eclipse will party over the file anyway, why it is checked in?
 - And if it has to be checked in, shouldn't the java version be aligned with our currently supported lowest version (8) ?

Thanks all.

		/Rod