patch 7.4.2288

Problem:    MS-Windows build instructions are clumsy. "dosbin" doesn't build.
Solution:   Add rename.bat. Fix building "dosbin".

tools/rename.bat

@@ -0,0 +1,6 @@
+mv vim.exe vimw32.exe
+mv tee/tee.exe teew32.exe
+mv xxd/xxd.exe xxdw32.exe
+mv vim.pdb vimw32.pdb
+mv install.exe installw32.exe
+mv uninstal.exe uninstalw32.exe