Run eslint autofix, tidy up spacing and adjust eslint rules

.eslintrc.js

@@ -41,7 +41,7 @@ module.exports = {
     "no-cond-assign": ["warn"],
     "no-fallthrough": ["warn"],
     "no-undef": ["error"],
-    "no-unused-vars": ["error"],
+    "no-unused-vars": ["warn"],
     "no-use-before-define": ["warn", { "functions": false, "classes": false, "variables": false }],
     "no-useless-escape": ["warn"],
     "no-useless-return": ["warn"],
@@ -53,9 +53,11 @@ module.exports = {
     "padded-blocks": ["warn", { "blocks": "never", "switches": "never", "classes": "never" }],
     "semi": ["error", "always"],
     "valid-typeof": ["warn"],
-    "no-eval": ["error"],
+    "no-eval": ["warn"],
     "no-implied-eval": ["error"],
     "no-debugger": ["warn"],
+    "no-unreachable": ["warn"],
+    "quotes": ["warn", "single", { "avoidEscape": true }]
   },
   extends: [
     "eslint:recommended"