*Jabil to build SunPower solar panels at Mexican plant *First step in implementing regional panel assembly *Financial terms not disclosed LOS ANGELES, June 8 (Reuters) - Solar power company SunPower Corp (SPWRA.O) said on Monday it had signed a contract with electronics maker Jabil Circuit Inc (JBL.N) to build solar panels in Mexico beginning in the second half of 2009. Jabil will start making solar panels for SunPower's North American solar customers in the second half of 2009, ...