Use wallet name in titles, replace hr dividers with grey stripe headers

Address titles now use wallet name instead of wallet index (e.g.
"Wallet 1 — Address 2" instead of "Address 1.2"). This applies to
the address detail page title, the home address labels, and the
addressTitle() helper used on confirmation pages.

Section dividers on the home screen are now full-width grey
background stripes instead of horizontal rules, visually breaking
the page into wallet sections and a recent transactions section.

src/popup/views/addressDetail.js

@@ -41,7 +41,7 @@ function show() {
     const wi = state.selectedWallet;
     const ai = state.selectedAddress;
     $("address-title").textContent =
-        wallet.name + " \u2014 Address " + (wi + 1) + "." + (ai + 1);
+        wallet.name + " \u2014 Address " + (ai + 1);
     const blockieEl = $("address-jazzicon");
     blockieEl.innerHTML = "";
     const img = document.createElement("img");