V8 3.0

V8 3.0

• Internal rewrite of object serialization to prepare for wasm
• Automatically convert raw vectors to/from Uint8Array in eval/get/assign
• Experimental wasm API + test
• Fix callback API crashes in V8 7.9+ (Jan Marvin, #70, #71, #75)
• Build with -DV8_ENABLE_CHECKS to get better error messages