Added a link to a James Bach talk on becoming a Software Testing Expert to the resources
Added a link to a paper by Michael Kelly on Using Heuristic Test Oracles
Added the "Lessons Learned in Software Testing" book to the resources list
Added definitions of heuristic oracles and consistency oracles
Added a basic definition of an oracle
Corrected some formatting
Added Cem Kaner's 4 problems with test oracles
Added a list of consistency oracles