patch 7.4.2069
Problem:    spell.c is too big.
Solution:   Split it in spell file handling and spell checking.
diff --git a/src/proto.h b/src/proto.h
index 660abc9..95b065e 100644
--- a/src/proto.h
+++ b/src/proto.h
@@ -158,6 +158,7 @@
 # endif
 # include "search.pro"
 # include "spell.pro"
+# include "spellfile.pro"
 # include "syntax.pro"
 # include "tag.pro"
 # include "term.pro"