Bypassuac/psh option

This will give the option to drop an exe or use psh if uac is turned off.  The lib can be used for post exploitation to drop an exe or usepowershell and then execute it with the runas command.  I have used the lib for both bypassuac and ask. #2551
Not a blocker, but Ruby style says that method definitions should be written like:

```
def foo(a = nil, b = 'adfadf', ...)
```

IOW, spaces between arguments, and spaces on either side of the = when used.