3a56ecc677 Add consts to Params for individual networks (Tobin C. Harding)
Pull request description:
Add consts to the `Params` type for the individual networks.
ACKs for top commit:
apoelstra:
ACK 3a56ecc677
Kixunil:
ACK 3a56ecc677
sanket1729:
ACK 3a56ecc677
Tree-SHA512: 0d265a14dd6a591a267da5381d3dcfd0d313f950dec4922f96d25349047d0c8a366c41dcdc1fc523fe4b178ec6a00b717bda25286625e222194f345cee5e7a97