patch 8.1.2157: libvterm source files missing from distribution

Problem:    Libvterm source files missing from distribution.
Solution:   Rename source files. (closes #5065)

Author: brammool

Filelist

@@ -296,11 +296,11 @@ SRC_ALL =	\
 		src/libvterm/src/encoding/uk.inc \
 		src/libvterm/src/encoding/uk.tbl \
 		src/libvterm/src/keyboard.c \
-		src/libvterm/src/termmouse.c \
+		src/libvterm/src/mouse.c \
 		src/libvterm/src/parser.c \
 		src/libvterm/src/pen.c \
 		src/libvterm/src/rect.h \
-		src/libvterm/src/termscreen.c \
+		src/libvterm/src/screen.c \
 		src/libvterm/src/state.c \
 		src/libvterm/src/unicode.c \
 		src/libvterm/src/utf8.h \

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    2157,
 /**/
     2156,
 /**/