chainreg: add Config, move chainparams.go

Creates a Config that initializes the chainregistry struct in the
lnd package. Also moves all of chainparams.go to the chainreg
package.

pilot.go

@@ -9,6 +9,7 @@ import (
 	"github.com/btcsuite/btcd/wire"
 	"github.com/btcsuite/btcutil"
 	"github.com/lightningnetwork/lnd/autopilot"
+	"github.com/lightningnetwork/lnd/chainreg"
 	"github.com/lightningnetwork/lnd/lncfg"
 	"github.com/lightningnetwork/lnd/lnwire"
 	"github.com/lightningnetwork/lnd/tor"
@@ -76,7 +77,7 @@ type chanController struct {
 	minConfs      int32
 	confTarget    uint32
 	chanMinHtlcIn lnwire.MilliSatoshi
-	netParams     bitcoinNetParams
+	netParams     chainreg.BitcoinNetParams
 }
 
 // OpenChannel opens a channel to a target peer, with a capacity of the
@@ -134,8 +135,8 @@ var _ autopilot.ChannelController = (*chanController)(nil)
 // interfaces needed to drive it won't be launched before the Manager's
 // StartAgent method is called.
 func initAutoPilot(svr *server, cfg *lncfg.AutoPilot,
-	chainCfg *lncfg.Chain, netParams bitcoinNetParams) (*autopilot.ManagerCfg,
-	error) {
+	chainCfg *lncfg.Chain, netParams chainreg.BitcoinNetParams) (
+	*autopilot.ManagerCfg, error) {
 
 	atplLog.Infof("Instantiating autopilot with active=%v, "+
 		"max_channels=%d, allocation=%f, min_chan_size=%d, "+