Implement Sass (#568)

* Move all images to assets/img

* Move all scripts to assets/js

* Move all webfonts to assets/webfonts

* Move all files to assets/files

* Move css to assets/css and add imports

* Adjust all references to assets folder

* Fix tor icon path

* Rewrite custom css to sass and add variables

* Change ?v on style.css to 5.

* Enable Sass minification

* Remove CryptoPaper-full.7z

assets/img/flags/cf.svg

@@ -0,0 +1,15 @@
+<svg xmlns="http://www.w3.org/2000/svg" height="480" width="640">
+  <defs>
+    <clipPath id="a">
+      <path fill-opacity=".67" d="M-12.355 32h640v480h-640z"/>
+    </clipPath>
+  </defs>
+  <g clip-path="url(#a)" fill-rule="evenodd" transform="translate(12.355 -32)">
+    <path fill="#00f" d="M-52 32h719.29v118.94H-52z"/>
+    <path fill="#ff0" d="M-52 391.65h719.29V512H-52z"/>
+    <path fill="#009a00" d="M-52 271.3h719.29v120.35H-52z"/>
+    <path fill="#fff" d="M-52 150.94h719.29v120.35H-52z"/>
+    <path fill="red" d="M247.7 32.474h119.88v479.53H247.7z"/>
+    <path fill="#ff0" d="M99.253 137.653L67.837 115.93l-31.314 21.937 10.87-36.717-30.457-23.118 38.14-.968 12.49-36.22 12.702 36.113 38.173.732-30.284 23.288"/>
+  </g>
+</svg>