#28 Added error creating to scrypt common; Introduced js function to access error creation; Updated binding.gyp
index.js wraps scrypt functions in js land for ease of use
#28 params and passwordhash using new error object
#28 Scrypt error: A means to obtain the error object from JS land
#27 Refactored params. Neater code means less chance of memory leak
#26 Neatened and DRY'd code
#28 MakeErrorObject is overloaded to be neater; files now referring to the overloaded function