Adds enhanced support for network capture decryption

[cgranleese-r7]

This pull request adds enhanced support for network capture decryption. By writing to the sslkeylogfile it enable network capture decryption which is useful to decrypt TLS traffic in wireshark.

Needs tested with Metasploit-Framework, to do this add the following to the Metasploit-Framework Gemfile:

gem "rex-socket", path: "../rex-socket"

Then bundle install.

Verification

• Start msfconsole
• Use scanner/http/title
• Run run rhosts=https://www.google.com verbose=true httptrace=true sslkeylogfile=./sslkeylogfile.txt
• The module should complete
• Run ls -la and you should now see a file called sslkeylogfile.txt