Implement plain view

This implements a way to access plain blobs by path (similar to the
tree view) instead of by sha1.

Signed-off-by: Lars Hjemli <hjemli@gmail.com>
diff --git a/html.h b/html.h
index 2bde28d..49462a2 100644
--- a/html.h
+++ b/html.h
@@ -3,6 +3,7 @@
 
 extern int htmlfd;
 
+extern void html_raw(const char *txt, size_t size);
 extern void html(const char *txt);
 extern void htmlf(const char *format,...);
 extern void html_status(int code, int more_headers);