Change the cgit layout

This modifies and hopefully improves the layout of all cgit pages:

  * Remove the header from all pages and replace it with a sidebar;
    most pages have sufficient width but many needs more height.

  * Add a dropdown-box to switch between branches, using a one-liner
    javascript to reload the current page in context of the selected branch.

  * Include refs found below refs/archives in the sidebar, appearing as a
    set of menuitems below a 'download' heading.

  * Include the brand new cgit logo

Signed-off-by: Lars Hjemli <hjemli@gmail.com>

shared.c

@@ -303,6 +303,37 @@ char *trim_end(const char *str, char c)
 	return s;
 }
 
+char *strlpart(char *txt, int maxlen)
+{
+	char *result;
+
+	if (!txt)
+		return txt;
+
+	if (strlen(txt) <= maxlen)
+		return txt;
+	result = xmalloc(maxlen + 1);
+	memcpy(result, txt, maxlen - 3);
+	result[maxlen-1] = result[maxlen-2] = result[maxlen-3] = '.';
+	result[maxlen] = '\0';
+	return result;
+}
+
+char *strrpart(char *txt, int maxlen)
+{
+	char *result;
+
+	if (!txt)
+		return txt;
+
+	if (strlen(txt) <= maxlen)
+		return txt;
+	result = xmalloc(maxlen + 1);
+	memcpy(result + 3, txt + strlen(txt) - maxlen + 4, maxlen - 3);
+	result[0] = result[1] = result[2] = '.';
+	return result;
+}
+
 void cgit_add_ref(struct reflist *list, struct refinfo *ref)
 {
 	size_t size;