Added warnings when attempting to use reserved Javascript keywords as variable or functions names.
Added warnings when attempting to use reserved Javascript keywords as variable or functions names.

Signed-off-by: Vladimir Sedach <9b2fcaa610d682dc31fcb77caf157992423df5b1@gmail.com> 

VincentToups/parenscript,JackDanger/parenscript,JackDanger/parenscript,3b/parenscript,fredericksilva/Parenscript,JackDanger/parenscript,manuel/parenscript,JDReutt/parenscript,vsedach/Parenscript