Add Windows post module for reading/searching Outlook e-mail

This module allows to read and search e-mails present in Outlook installations. It is using powershell in order to search the e-mails.

When connecting to Outlook using powershell, a security popup appears. WinAPI is used to automatically click on the popup, so access is allowed.

This module is tested on Windows 8.1 x64 with Outlook 2013.
Rex itself has base64 decoding/encoding methods, you don't really need this.