add N&N for PDE 503 and 527 (#109)

* add N&N for PDE 503 and 527

Refs: https://github.com/eclipse-pde/eclipse.pde/issues/503
Refs: https://github.com/eclipse-pde/eclipse.pde/issues/527

* fixup: address review comments

* fixup: add PR links for back-referencing
3 files changed