Appending value arrays is now the default

• When merging value arrays, append instead of merging values for keys.
  • Swap the flag over from FLAG_APPEND_VALUE_ARRAY to FLAG_MERGE_VALUE_ARRAY
• Add the flag: FLAG_UNIQUE_VALUE_ARRAY to remove unique values when merging value arrays

Initial Release

Initial release:

• Supports merging flat and recursive arrays
• Allows you to choose how to merge the values
  • e.g. last, lastNonNull, first, firstNonNull, sum, product, random, etc
• Optionally append value arrays