Generation of slugs and new urls to handle slugs

- TODO: redirect to correct slug if not found.

bookwyrm/templates/book/book.html

@@ -267,7 +267,7 @@
                 {% if user_statuses.review_count or user_statuses.comment_count or user_statuses.quotation_count %}
                 <nav class="tabs">
                     <ul>
-                        {% url 'book' book.id as tab_url %}
+                        {% url 'book' book.id book.name|slugify as tab_url %}
                         <li {% if tab_url == request.path %}class="is-active"{% endif %}>
                             <a href="{{ tab_url }}#reviews">{% trans "Reviews" %} ({{ review_count }})</a>
                         </li>

bookwyrm/templates/book/file_links/edit_links.html

@@ -15,7 +15,7 @@
 
     <nav class="breadcrumb subtitle" aria-label="breadcrumbs">
         <ul>
-            <li><a href="{% url 'book' book.id %}">{{ book|book_title }}</a></li>
+            <li><a href="{% url 'book' book.id book.name|slugify %}">{{ book|book_title }}</a></li>
             <li class="is-active">
                 <a href="#" aria-current="page">
                     {% trans "Edit links" %}