New Reflection Powershell Payload

Adds Powershell payload which, unlike existing payloads does not
drop any temporary files onto the target's computer.  All needed
methods are dynamically loaded via reflection.
Added Template

New template for previous commit.
Update source
Merge for retab
Retab changes for PR #2307
Merge for retab
Retab changes for PR #2288
Merge for retab
Retab changes for PR #1910
Merge pull request #11 from tabassassin/retab/pr/2288

Retab/pr/2288
Merge for retab
Retab changes for PR #1473
Merge pull request #23 from tabassassin/retab/pr/1473

Retab/pr/1473
Merge pull request #1 from tabassassin/retab/pr/2307

Retab/pr/2307 landed as requested.
Merge branch 'master' of github.com:rapid7/metasploit-framework into enum_ad_perf
Use meterp dns lookup
Swap x64/x86 detection
Use meterpreter dns resolve
Submodule
Initialize strings fool