Add the ability to specify mode in Rex output file

* Because sometimes you might want to append
* Preserves original hardcoded 'wb' as default
* http://pubs.opengroup.org/onlinepubs/009695399/functions/fopen.html
Add module for MS14-064 bypassing UAC through python for windows
Update target info
Refactor create packager methods
this spec needs to use the username factory

:metasploit-credential_public factory will randomly
return either a Username or BlankUsername and thus is
not appropriate for when you want tos et an explicit Username.
The :metasploit_credential_username factory should be used for this
instead

MSP-11609
use latest version of metasploit-credential

MSP-11609
metasploit-credential bump to 0.13.3

MSP-11609
Land #4197, blank username failure fix
Fixes lack of support for MetasploitV5 tag

 #4184

* Appears to have been overlooked somehow in the pre-BlackHat crunch
* V5 will not support credentials
* We are implementing full-workspace zip import/export for credentials
Land #4196 - MS14-064 bypassing UAC
Land #4198, @trosen-r7's fixes to XML import.
Minor typos and grammar fixes
Fix newly introduced typo.
Land #4192, enable specifying mode for Rex output file
Land #4201, release fixes