Use abab for cross-platform atob/btoa, fix rollup config

package.json

@@ -53,6 +53,7 @@
   "devDependencies": {
     "@babel/core": "^7.4.5",
     "@babel/preset-env": "^7.4.5",
+    "abab": "^2.0.0",
     "almond": "~0.3.0",
     "es6-promise": "^4.1.0",
     "eslint": "4.19.1",

rollup.config.js

@@ -19,7 +19,7 @@ export default [
             commonjs(),
             globals(),
             babel({
-                exclude: ['node_modules/**'],
+                babelrc: false,
                 presets: [
                     ['@babel/preset-env', {
                         targets: {
@@ -43,7 +43,7 @@ export default [
             commonjs(),
             globals(),
             babel({
-                exclude: ['node_modules/**'],
+                babelrc: false,
                 presets: [
                     ['@babel/preset-env', {
                         targets: {
@@ -58,15 +58,15 @@ export default [
     // CommonJS (for Node) and ES module (for bundlers) build.
     {
         input: 'src/strophe.js',
-        external: ['window', 'md5'],
+        external: ['window', 'abab'],
         output: [
             { file: pkg.main, format: 'cjs' },
             { file: pkg.module, format: 'es' }
         ],
         plugins: [
             globals(),
             babel({
-                exclude: ['node_modules/**'],
+                babelrc: false,
                 presets: [
                     ['@babel/preset-env']
                 ]

src/core.js

@@ -6,6 +6,8 @@
 */
 /*global define, document, sessionStorage, setTimeout, clearTimeout, ActiveXObject, DOMParser, btoa, atob, module */
 
+import { atob, btoa } from 'abab'
+
 import MD5 from './md5';
 import SHA1 from './sha1';
 import utils from './utils';