patch 8.0.0785: wildcards are not expanded for :terminal

Problem:    Wildcards are not expanded for :terminal.
Solution:   Add FILES to the command flags. (Yasuhiro Matsumoto, closes #1883)
            Also complete commands.
diff --git a/src/ex_cmds.h b/src/ex_cmds.h
index dd54981..977b01a 100644
--- a/src/ex_cmds.h
+++ b/src/ex_cmds.h
@@ -1484,7 +1484,7 @@
 			NEEDARG|EXTRA|TRLBAR|NOTRLCOM|CMDWIN,
 			ADDR_LINES),
 EX(CMD_terminal,	"terminal",	ex_terminal,
-			RANGE|NOTADR|EXTRA|TRLBAR|CMDWIN,
+			RANGE|NOTADR|FILES|TRLBAR|CMDWIN,
 			ADDR_OTHER),
 EX(CMD_tfirst,		"tfirst",	ex_tag,
 			RANGE|NOTADR|BANG|TRLBAR|ZEROR,