Patches UA and PROXY in metsrv when running migrate
msftidy'd
De-committing based on suggestions from Meatballs1 and jlee-r7.
Provides methods to patch metsrv stagers with options.
Cleaned up indents.
Refactored expiration and timeout logic in client_core.rb
Mitigates excessive use of lookup operator (hopefully adds clarity)
Uses a hash for options as opposed to numerous methods on blob
Fix #4378 - Do exception handling

Fix #4378
Take full advantage of the check command
Reworked to avoid extending String class on blob per hdm's rec.
Resolves #4275 - Configurable variable name as an option

Resolves #4275
Update rpsec
This oracle scheduler exploit hangs if not vuln

When this exploit gets run against a system that isn't vulnerable
it can hang for a signifigant ammount of time. This change uses the check
method on the exploit to see whether it should proceed. Don't try to exploit
the host if it's not vulnerable.
Land #4403, msfvenom configurable variable name
Land #4404, Oracle scheduler exploit fix
Land #4402, ms12_020_check NilClass fix
Refactors metsrv patching in reverse_http.rb
Refactors metsrv patching in reverse_hop_htt.rb
Patch UA/Proxy settings during migration, lands #3632