fix msysgit-install.cmd

msysgit-install.cmd was wrong in many points. This patch fixes various
bugs.

contrib/msysgit-install.cmd

@@ -1,3 +1,5 @@
+@echo off
+
 set STARTUP_PATH=%~d0%~p0
 if "%HOME%" == "" goto sethome
 goto makedir
@@ -7,15 +9,14 @@ echo set HOME variable
 set HOME=%UserProfile%
 
 :makedir
-if not exist %HOME%\bin goto :copyshflags
+if exist %HOME%\bin goto copyshflags
 echo make bin folder
 mkdir %HOME%\bin
 
+:copyshflags
 set MSYS_BIN=%HOME%\bin
-
 echo Installing git-now to "%MSYS_BIN%"
 
-:copyshflags
 echo copy shFlags
 copy %STARTUP_PATH%..\shFlags\src\shflags %MSYS_BIN%\gitnow-shFlags