Fix urlPath support, let CodiMD be served from a subpath correctly

Webpack now uses relative paths for resources linked from by static
snippets. A templated <base> tag has been introduced in headers
so app.js can set the base URL at runtime.

Signed-off-by: Enrico Guiraud <enrico.guiraud@cern.ch>

public/views/includes/scripts.ejs

@@ -1,4 +1,4 @@
-<script src="<%= webpackConfig.output.baseUrl %>/config"></script>
+<script src="config"></script>
 <% for (var js in htmlWebpackPlugin.files.js) { %>
-<script src="<%= webpackConfig.output.baseUrl %><%= htmlWebpackPlugin.files.js[js] %>" defer></script>
+<script src="<%= htmlWebpackPlugin.files.js[js] %>" defer></script>
 <% } %>