FEATURE CUSTOMIZATION
The following options all turn on or off certain JavaScript features. These features are part of standard ECMAScript, but you may choose to disable certain features to conserve space for low-memory systems.
JSE_SAVE_FUNCTION_TEXT (on, off if JSE_MIN_MEMORY is on or JSE_COMPILER is off)
JSE_ALWAYS_IMPLICIT_THIS (off)
JSE_ALWAYS_IMPLICIT_PARENTS (off)