[TASK] Clarify documentation for AOP method() and class() (Revision 1)

Add some hints regarding matching on interfaces.

Releases: master, 2.1
Change-Id: Icfe4adc361de71ee4b22b353d914756f4d6ea2a6
Revision-Id: d2bfbd4ecc38b203b6f89c248f6f36dbdef6385c