Per XLS-0095, we are taking steps to rename ripple(d) to xrpl(d).
This change specifically removes all copyright notices referencing Ripple, XRPLF, and certain affiliated contributors upon mutual agreement, so the notice in the LICENSE.md file applies throughout. Copyright notices referencing external contributions remain as-is. Duplicate verbiage is also removed.
This change:
* Simplifies the `TxMeta` constructors - both were setting the same set of fields, and to make it harder for future bugs to arise and keep the code DRY, we can combine those into one helper function.
* Removes an unused constructor.
* Renames the variables to avoid Hungarian naming.
* Removes a bunch of now-unnecessary helper functions.
