WMIC Post Mixin

This starts to utilize the ExtAPI clipboard functionality to retrieve WMI results. Something that was previously required file IO as WMIC does funny things with its stdout. N.B. Using the clipboard as output does not capture ERROR conditions so we cant see why it has failed but know it has if we get no text back at all. 

The Local WMI module is now slightly more responsive as it can detect a successful command and skip a host if the command fails.

The post/windows/gather/wmic_command can now target another host with credentials or using the current user's credentials. 

The wmic_query command can be used to retrieve any query but is not currently implemented in any post modules.
wmic_query("qfe list") will bring back all the current patches:

```
Caption                                     CSName  Description      FixComments  HotFixID                                         InstallDate  InstalledBy          InstalledOn  Name  ServicePackInEffect  Status  
http://support.microsoft.com/kb/2899189     DRAKE   Update                        KB2899189_Microsoft-Windows-CameraCodec-Package               NT AUTHORITY\SYSTEM  12/12/2013                                      
http://support.microsoft.com/?kbid=2862152  DRAKE   Security Update               KB2862152                                                     NT AUTHORITY\SYSTEM  11/13/2013                                      
http://support.microsoft.com/?kbid=2868626  DRAKE   Security Update               KB2868626                                                     NT AUTHORITY\SYSTEM  11/13/2013
```