Catch and log early init errors

Prior to this change, it was possible for errors initializing or waiting
on plugins to go undetected. Errors in wait() would bubble up to the
"no-network" error, which has been even more confusing for users.

Related, but does not fix:
#1847

src/core/core.js

@@ -66,13 +66,17 @@ class Core {
    * @returns {Promise}
    */
   prepare(file) {
-    return Promise.all([this.readConfigFile(file), this.plugins.init()]).then(
+    return Promise.all([
+      this.readConfigFile(file),
+      this.plugins.init().catch(e => errors.toUser(e, "initializing plugins")),
+    ]).then(
       () => {
         if (this.props.config) {
           this.selectOs();
         } else {
           const wait = this.plugins
             .wait()
+            .catch( e => errors.toUser(e, "plugin wait()"))
             .then(device => api.resolveAlias(device))
             .catch(
               e =>