Costs are yet to be tweaked.
This patch is joint work between:
Milo Davis <davis.mil@husky.neu.edu>
Benjamin Canou <benjamin@canou.fr>
Pierre Chambart <pierre.chambart@ocamlpro.com>
Now a tez cent is 10_000L. All constants are now in the
Constants_repr module and expressed as multiples of one_cent.
Add new function Qty_repr.mul_exn to multiply `tez` by `int`
eg. `10 tez = Tez_repr.(mul_exn one 10)`
`10 cents = Tez_repr.(mul_exn one_cents 10)`
Remove `Tez.{to,of}_cents` and replace them with `Tez.{to,of}_mutez`.
