out-of-tree build support broken / missing

[Heike Jagode]

This requires a substantial rewriting of configure.in; and even more substantial testing with components, different OS support, etc.

[Heike Jagode]

After poking around the current autoconf implementation, we've decided to postpone support for out-of-tree build. We are in the process of replacing autoconf with cmake, and the out-of-tree feature will be supported in the new PAPI cmake version.