Gov. C. L. "Butch" Otter has signed laws to eliminate teacher job protections and early retirement, restrict collective bargaining and introduce merit pay in Idaho.   Otter signed the two bills Thursday, saying he was committed to working with lawmakers on a third piece of the plan to overhaul K-12 public education in Idaho.  The biggest piece of the reform package calls for boosting technology in the classroom and remains in the Idaho Senate, where it has undergone significant changes amid concerns it would increase class sizes and cut 770 teaching jobs.      Lawmakers expect the revamped bill to be ready for introduction Friday.  Public schools chief Tom Luna unveiled the reform proposal in January with backing from Otter and the plan has dominated the 2011 session, triggering teacher and student protests.