Massive JavaScript cleanup

- Use JSX for templates
- Docblock/comment everything
- Mostly passes ESLint (still some work to do)
- Lots of renaming, refactoring, etc.

CSS hasn't been updated yet.

js/lib/utils/string.js

@@ -1,5 +1,38 @@
-export function dasherize(string) {
-  return string.replace(/([A-Z])/g, function ($1) {
-    return '-' + $1.toLowerCase();
-  });
+/**
+ * Truncate a string to the given length, appending ellipses if necessary.
+ *
+ * @param {String} string
+ * @param {Number} length
+ * @param {Number} [start=0]
+ * @return {String}
+ */
+export function truncate(string, length, start = 0) {
+  return (start > 0 ? '...' : '') +
+    string.substring(start, start + length) +
+    (string.length > start + length ? '...' : '');
+}
+
+/**
+ * Create a slug out of the given string. Non-alphanumeric characters are
+ * converted to hyphens.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export function slug(string) {
+  return string.toLowerCase()
+    .replace(/[^a-z0-9]/gi, '-')
+    .replace(/-+/g, '-')
+    .replace(/-$|^-/g, '') || '-';
+}
+
+/**
+ * Strip HTML tags and quotes out of the given string, replacing them with
+ * meaningful punctuation.
+ *
+ * @param {String} string
+ * @return {String}
+ */
+export function getPlainContent(string) {
+  return $('<div/>').html(string.replace(/(<\/p>|<br>)/g, '$1 ')).text();
 }