updated for version 7.4.449
Problem:    Can't easily close the help window. (Chris Gaal)
Solution:   Add ":helpclose". (Christian Brabandt)
diff --git a/src/proto/ex_cmds.pro b/src/proto/ex_cmds.pro
index a94f5d0..8757637 100644
--- a/src/proto/ex_cmds.pro
+++ b/src/proto/ex_cmds.pro
@@ -44,6 +44,7 @@
 void free_old_sub __ARGS((void));
 int prepare_tagpreview __ARGS((int undo_sync));
 void ex_help __ARGS((exarg_T *eap));
+void ex_helpclose __ARGS((exarg_T *eap));
 char_u *check_help_lang __ARGS((char_u *arg));
 int help_heuristic __ARGS((char_u *matched_string, int offset, int wrong_case));
 int find_help_tags __ARGS((char_u *arg, int *num_matches, char_u ***matches, int keep_lang));