tools: enable stricter linting in lib directory

Enable ESLint 4.x linting and disable legacy linting in the lib
directory.

While doing this, some indentation in the .eslintrc.yaml file itself was
noticed to be incorrect. Fixed that too.

Author: Trott

.eslintrc.yaml

@@ -102,17 +102,17 @@ rules:
   func-name-matching: error
   func-style: [error, declaration, {allowArrowFunctions: true}]
   # indent: [error, 2, {ArrayExpression: first,
-  #                 CallExpression: {arguments: first},
-  #                 FunctionDeclaration: {parameters: first},
-  #                 FunctionExpression: {parameters: first},
-  #                 MemberExpression: off,
-  #                 ObjectExpression: first,
-  #                 SwitchCase: 1}]
+  #                     CallExpression: {arguments: first},
+  #                     FunctionDeclaration: {parameters: first},
+  #                     FunctionExpression: {parameters: first},
+  #                     MemberExpression: off,
+  #                     ObjectExpression: first,
+  #                     SwitchCase: 1}]
   indent-legacy: [error, 2, {ArrayExpression: first,
-                         CallExpression: {arguments: first},
-                         MemberExpression: 1,
-                         ObjectExpression: first,
-                         SwitchCase: 1}]
+                             CallExpression: {arguments: first},
+                             MemberExpression: 1,
+                             ObjectExpression: first,
+                             SwitchCase: 1}]
   key-spacing: [error, {mode: minimum}]
   keyword-spacing: error
   linebreak-style: [error, unix]

lib/.eslintrc.yaml

@@ -1,4 +1,13 @@
 rules:
+  indent: [error, 2, {ArrayExpression: first,
+                      CallExpression: {arguments: first},
+                      FunctionDeclaration: {parameters: first},
+                      FunctionExpression: {parameters: first},
+                      MemberExpression: off,
+                      ObjectExpression: first,
+                      SwitchCase: 1}]
+  indent-legacy: 0
+
   # Custom rules in tools/eslint-rules
   require-buffer: error
   buffer-constructor: error