# Functions
NewNSNumber reads a NSNumber from bytes.
NewNSNumberFromUFloat64 create NSNumber of type 0x06 with a 8 byte int as value.
NewNSNumberFromUInt32 create NSNumber of type 0x03 with a 4 byte int as value.
NewNSNumberFromUInt64 create NSNumber of type 0x04 with a 8 byte int as value.
ParseLengthAndMagic checks if if the given byte array is longer or equal the uint32 in the first 4 bytes, and if the magic value in the second 4 bytes equals the supplied magic and returns the length, a slice of the bytes without length and magic or an error.
WriteLengthAndMagic just writes length and magic as uint32 4 byte values into the given array.
# Constants
NumberValueMagic is vbmn in little endian ascii ==> nmbv.