Fix eslint warnings

Since we are about to release it's time to finally fix our linting. This
patch basically runs eslint --fix and does some further manual fixes.
Also it sets up eslint to fail on every warning on order to make
warnings visable in the CI process.

There should no functional change be introduced.

Signed-off-by: Sheogorath <sheogorath@shivering-isles.com>

package.json

@@ -6,7 +6,7 @@
   "license": "AGPL-3.0",
   "scripts": {
     "test": "npm run-script eslint && npm run-script jsonlint && npm run-script mocha-suite",
-    "eslint": "node_modules/.bin/eslint lib public test app.js",
+    "eslint": "node_modules/.bin/eslint --max-warnings 0 lib public test app.js",
     "jsonlint": "find . -not -path './node_modules/*' -type f -name '*.json' -o -type f -name '*.json.example' | while read json; do echo $json ; jq . $json; done",
     "mocha-suite": "NODE_ENV=test CMD_DB_URL=\"sqlite::memory:\" mocha --exit",
     "standard": "echo 'standard is no longer being used, use `npm run eslint` instead!' && exit 1",