Added capability to hide the shim'd application

[cs96and]

Adds a new hide capability, which hides the shim'd application when it is run. This is useful for writing a shim around a .bat or .sh file so that it runs without a command window popping up.

E.g.

shmake -i c:\cygwin\bin\bash.exe -o "run-my-script.exe" -a "c:\path\to\my-script.sh %s" -c no-kill -c hide

shmake -i c:\Windows\system32\cmd.exe -o "run-my-bat.exe" -a "/c c:\path\to\my-script.bat %s" -c no-kill -c hide