Remove libaxolotl dependency on textsecure/errors.js

Let libaxolotl throw a generic error instead of a replayable error, and
add an helper function in libtextsecure's axolotl_wrapper to catch and
convert from the generic error to the replayable one. This allows the
ReplayableError to remain a libtextsecure-level concept only.

Somewhat unrelatedly, but nearby, fix some whitespace and add missing
semicolon.

libtextsecure/libaxolotl_concat.js

@@ -37001,8 +37001,7 @@ window.axolotl.protocol = function() {
                 if (open_session !== undefined)
                     closeSession(open_session); // To be returned and saved later
             } else {
-                // ...otherwise create an error that the UI will pick up and ask the user if they want to re-negotiate
-                throw new textsecure.IncomingIdentityKeyError(encodedNumber, getString(message.encode()));
+                throw new Error('Unknown identity key');
             }
         }
         return initSession(false, preKeyPair, signedPreKeyPair, encodedNumber, toArrayBuffer(message.identityKey), toArrayBuffer(message.baseKey), undefined)