Minor callback speed optimizations

Modified: src/JSTools/Native.inc
Minor callback speed optimizations

Modified: src/JSTools/Native.inc
Added callback error handlers.

Throwing an unhandled error in the midst of a native callback will exit program execution.

If a callback parameter cannot be converted to a javascript value, the program will exit.

Modified: bin/buildnum
Modified: src/JSTools/Native.inc
Improved closure support

Modified: bin/buildnum
Modified: src/JSTools/Native.inc