js: implement import/delete Key, some fixes

--

* Keyring.js
   - implemented importKey: importing one or more armored public key
     blocks.
   - implemented deleteKey: deleting a public Key from gpg.

* Key.js renamed property Key.armor to Key.armored

* Helpers.js: toKeyIDArray does not complain anymore if there are no
  keys. Not having Keys in e.g. signing keys in encrypt is legitimate
  and common, the complaints were getting spammy

* Errors.js: gpgme_errors now always pass an optional additional
  message, for easier debugging in minified code

* Connection.js: Fix in gpgme-json responses containing objects

* eslintrc.json: Start using eslint. A cleanup to conform to it is not
  done yet

* Added further tests for the new functionality

1 files changed, 0 insertions, 2 deletions

diff --git a/lang/js/src/Helpers.js b/lang/js/src/Helpers.js
index b26f40fb..5064d03e 100644
--- a/lang/js/src/Helpers.js
+++ b/lang/js/src/Helpers.js
@@ -29,7 +29,6 @@ import { GPGME_Key } from "./Key";
 
 export function toKeyIdArray(input){
     if (!input){
-        gpgme_error('MSG_NO_KEYS');
         return [];
     }
     if (!Array.isArray(input)){
@@ -61,7 +60,6 @@ export function toKeyIdArray(input){
         }
     }
     if (result.length === 0){
-        gpgme_error('MSG_NO_KEYS');
         return [];
     } else {
         return result;