Make JS X Again

* Configure the project to allow the use of JSX in .jsx files.
* Add linting for JSX.
* Rewrite most existing code that uses `createElement` to use JSX syntax.
* Stop importing `createElement as e`. That's what the minifier is for. And we don't have to write it manually so much now because of JSX syntax.

webpack.common.js

@@ -8,6 +8,7 @@ module.exports = {
 		avalon: './src/main.js'
 	},
 	resolve: {
+		extensions: ['.js', '.jsx'],
 		alias: {
 			res: path.resolve(__dirname, 'res/'),
 			styles: path.resolve(__dirname, 'styles/'),
@@ -45,6 +46,11 @@ module.exports = {
 				}
 			}]
 		},
+		{
+			test: /\.jsx$/,
+			exclude: /node_modules/,
+			loader: 'babel-loader'
+		},
 		{
 			test: /\.(graphql|gql)$/,
 			exclude: /node_modules/,