css: h2 wrap instead of scroll.

Previously, h2 would scroll horizontally to accommodate very long page
titles, such as ngx_http_random_index_module. This is effective but some
browsers always display scrollbars, even when the title does not overflow.
As it is not possible to treat underscore as a wrappable character with the
current content generator, we now wrap very long words (mid-word) when necessary.

Author: lcrilly

css/style_en.css

@@ -66,7 +66,7 @@ h2 {
     font-size: 2rem;
     line-height: 2.25rem;
     margin: 1rem 0 .5rem 0;
-    overflow-x: scroll;
+    overflow-wrap: break-word;
 }
 
 h4 {

css/style_ru.css

@@ -66,7 +66,7 @@ h2 {
     font-size: 2rem;
     line-height: 2.25rem;
     margin: 1rem 0 .5rem 0;
-    overflow-x: scroll;
+    overflow-wrap: break-word;
 }
 
 h4 {