School foundations and PTAs used to raise money for the extras – high-tech projectors and special field trips. But these days, private donations to schools have grown dramatically and are being used to prevent teacher layoffs, keep libraries open, and save music and foreign-language classes, California Watch reports. California K-12 foundations, PTAs and booster clubs raised about $1.3 billion in 2007, according to the most recent tax filings analyzed by the Public Policy Institute of California [1]. That’s up from $70 million in 1989, according to the institute…