Introduce html.h

All html-functions can be quite easily separated from the rest of cgit, so
lets do it; the only issue was html_filemode which uses some git-defined
macros so the function is moved into ui-shared.c::cgit_print_filemode().

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

ui-blob.c

@@ -1,4 +1,13 @@
+/* ui-blob.c: show blob content
+ *
+ * Copyright (C) 2008 Lars Hjemli
+ *
+ * Licensed under GNU General Public License v2
+ *   (see COPYING for full license text)
+ */
+
 #include "cgit.h"
+#include "html.h"
 
 void cgit_print_blob(struct cacheitem *item, const char *hex, char *path)
 {