patch 9.1.1051: tests: no support for env variables when running Vim in terminal

Problem:  tests: no support for env variables when running Vim in
          terminal
Solution: support the "env" argument in RunVimInTerminal(),
          close swapfiles properly in test_termcodes,
          use CheckFeature in test_termencoding

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 53cecb3..235c4f3 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1051,
+/**/
     1050,
 /**/
     1049,