Change the way the total balance is calculated

Instead of attempting to show an "how much you can spend" metric,
we're now showing a simpler "how much you have" metric instead.

- The balance now includes the on-chain balance (sum of utxos).

- It also includes funds held in channels with disconnected peers.

- It uses the total "msatoshi_to_us" instead of "spendable_msatoshi",
  which includes the channel reserve.

For more on the rational behind this changes, see:
#62 (comment)

client/src/model.js

@@ -5,8 +5,8 @@ import { dbg, getChannels, formatAmt, recvAmt, combine, isConnError } from './ut
 const msatbtc = big(100000000000) // msat in 1 btc
 
 const
-  sumChans = chans => chans.filter(c => c.peer.connected && c.chan.state === 'CHANNELD_NORMAL')
-                           .reduce((T, c) => T + Math.max(0, c.chan.spendable_msatoshi), 0)
+  sumChans = chans => chans.filter(c => c.chan.state === 'CHANNELD_NORMAL')
+                           .reduce((T, c) => T + Math.max(0, c.chan.msatoshi_to_us), 0)
 
 , fmtAlert = (s, unitf) => s.replace(/@\{\{(\d+)\}\}/g, (_, msat) => unitf(msat))
 
@@ -77,6 +77,7 @@ module.exports = ({ dismiss$, togExp$, togTheme$, togUnit$, page$, goHome$, goRe
     .startWith(null)
 
   // On-chain balance
+  // TODO: patch with known outgoing payments
   , obalance$ = funds$.map(funds => funds.outputs.reduce((T, o) => T+o.value*1000, 0))
       .distinctUntilChanged()
 

client/src/views/layout.js

@@ -12,13 +12,13 @@ const layout = ({ state: S, body }) =>
   , S.info ? footer(S) : ''
   ])
 
-const navbar = ({ unitf, cbalance, page }) =>
+const navbar = ({ unitf, cbalance, obalance, page }) =>
   nav(`.navbar.navbar-dark.bg-primary.mb-3`, div('.container', [
     a('.navbar-brand', { attrs: { href: '#/' } }, [
       page.pathname != '/' ? span('.icon.icon-left-open') : ''
     , 'Spark'
     ])
-  , cbalance != null ? span('.toggle-unit.navbar-brand.mr-0', unitf(cbalance)) : ''
+  , cbalance != null && obalance != null ? span('.toggle-unit.navbar-brand.mr-0', unitf(cbalance + obalance)) : ''
   ]))
 
 const footer = ({ info, btcusd, msatusd, rate, conf: { unit, theme, expert } }) =>