MDL-59761 eslint: support glob-based configuration

Since ESlint 4.1.0 [1], it's possible to support glob-based
configuration, this means we can move glob configuration out of grunt
and into the config file, which means tools will respect the glob rules
now too. :)

[1] http://eslint.org/blog/2017/06/eslint-v4.1.0-released

.eslintrc

@@ -68,7 +68,6 @@
     'no-fallthrough': 'error',
     'no-floating-decimal': 'warn',
     'no-global-assign': 'warn',
-    // Enabled by grunt for AMD modules: 'no-implicit-globals': 'error',
     'no-implied-eval': 'error',
     'no-invalid-this': 'error',
     'no-iterator': 'error',
@@ -192,5 +191,24 @@
         'message': 'Use AMD module "core/str" or M.util.get_string()'
     }],
 
-  }
+  },
+  overrides: [
+    {
+      files: ["**/yui/src/**/*.js"],
+      // Disable some rules which we can't safely define for YUI rollups.
+      rules: {
+        'no-undef': 'off',
+        'no-unused-vars': 'off',
+        'no-unused-expressions': 'off'
+      }
+    },
+    {
+      files: ["**/amd/src/*.js"],
+      // Check AMD with some slightly stricter rules.
+      rules: {
+        'no-unused-vars': 'error',
+        'no-implicit-globals': 'error'
+      }
+    }
+  ]
 }

Gruntfile.js

@@ -112,26 +112,9 @@ module.exports = function(grunt) {
             // Even though warnings dont stop the build we don't display warnings by default because
             // at this moment we've got too many core warnings.
             options: {quiet: !grunt.option('show-lint-warnings')},
-            amd: {
+            amd: {src: amdSrc},
-              src: amdSrc,
-              // Check AMD with some slightly stricter rules.
-              rules: {
-                'no-unused-vars': 'error',
-                'no-implicit-globals': 'error'
-              }
-            },
             // Check YUI module source files.
-            yui: {
+            yui: {src: ['**/yui/src/**/*.js', '!*/**/yui/src/*/meta/*.js']}
-               src: ['**/yui/src/**/*.js', '!*/**/yui/src/*/meta/*.js'],
-               options: {
-                   // Disable some rules which we can't safely define for YUI rollups.
-                   rules: {
-                     'no-undef': 'off',
-                     'no-unused-vars': 'off',
-                     'no-unused-expressions': 'off'
-                   }
-               }
-            }
         },
         uglify: {
             amd: {