misc improvements for library usage:

- app: allow custom serviceworker path, or disable altogether
- page download options: add warc/1.0 option
- ui: remove unused small style from chooser
ui: tweak initial refresh time to half second

bump to 1.5.1

src/misc.js

@@ -130,6 +130,8 @@ class AnimLogo extends FaIcon
   }
 }
 
+
+// ===========================================================================
 class WrModal extends LitElement
 {
   constructor() {
@@ -154,6 +156,11 @@ class WrModal extends LitElement
     .modal-card-head {
       background-color: var(--background, #97a1ff);
     }
+
+    .modal-card {
+      width: 100%;
+      max-width: var(--modal-width, 640px)
+    }
     `);
   }