How to run the autoconf generated testsuite with `make installcheck`?

[Simon Sobisch]

While the automake manual mentions the installcheck target it doesn't
leave a note where to find more information about this.

I assume this is about something like:

* adding a installcheck-local target to tests/Makefile.am
* in this target run the check-local target but set an environment
variable before
* in tests/atlocal.in check for this variable and adjust the path of the
tested binaries to use no path at all (=use the ones found in PATH)

Is this the correct approach?

Thank you for providing some experience / best practice about the
installcheck target,

Simon