patch 8.2.0156: various typos in source files and tests

Problem:    Various typos in source files and tests.
Solution:   Fix the typos. (Emir Sari, closes #5532)
diff --git a/Makefile b/Makefile
index 642d25c..7774b6e 100644
--- a/Makefile
+++ b/Makefile
@@ -153,7 +153,7 @@
 #   > msvc2015.bat
 # - Build the console binary:
 #   > nmake -f Make_mvc.mak
-# - Run the tests and check the ouput:
+# - Run the tests and check the output:
 #   > nmake -f Make_mvc.mak testclean
 #   > nmake -f Make_mvc.mak test
 # - Rename (using ../tools/rename.bat):