patch 8.1.2062: the mouse code is spread out

Problem:    The mouse code is spread out.
Solution:   Move all the mouse code to mouse.c. (Yegappan Lakshmanan,
            closes #4959)
diff --git a/Filelist b/Filelist
index 0a686f3..7c5a4f0 100644
--- a/Filelist
+++ b/Filelist
@@ -80,6 +80,7 @@
 		src/message_test.c \
 		src/misc1.c \
 		src/misc2.c \
+		src/mouse.c \
 		src/move.c \
 		src/mysign \
 		src/nbdebug.c \
@@ -231,6 +232,7 @@
 		src/proto/message.pro \
 		src/proto/misc1.pro \
 		src/proto/misc2.pro \
+		src/proto/mouse.pro \
 		src/proto/move.pro \
 		src/proto/netbeans.pro \
 		src/proto/normal.pro \