Add support for PPID spoofing

[phra]

will fix rapid7/metasploit-payloads#373

requires rapid7/metasploit-payloads#374

Verification

List the steps needed to make sure this thing works

• Start msfconsole
• spawn meterpreter
• use exploit/windows/local/payload_inject
• set payload windows/x64/meterpreter/reverse_https
• set lhost ...
• set lport ...
• set PPID ... (PPID to spoof for new agent)
• a new agent is spawned under the specified PPID

[bwatters-r7]

I had some time to play with this today.... it is a neat feature, but it is prickly.
I was able to get it to work by choosing a notepad process as the PPID, but I was unable to get anything else to work. Calc failed and crashed calc; edge failed and crashed edge. Svchosts also failed. Occasionally I got Access Denied errors, but also, sometimes the spawned process just crashed and took the parent process with it.

[phra]

@bwatters-r7 yes, some processes are different from others. i have tested it with explorer.exe and that works too. basically it's not a bug of the code, but how the OS behaves.

[bwatters-r7]

Release Notes

This PR adds functionality to the process library and the exploit/windows/local/payload_inject module to specify a PPID value when creating a process.