ppr_flatten_rec update, RDI submodule, and refactor

This commit contains a few changes for the ppr_flatten_rec local windows
exploit. First, the exploit binary itself:

* Updated to use the RDI submodule.
* Updated to build with VS2013.
* Updated to generate a binary called `ppr_flatten_rc.x86.dll`.
* Invocation of the exploit requires address of the payload to run.

Second, the module in MSF behaved a little strange. I expected it to create
a new session with system privs and leave the existing session alone. This
wasn't the case. It used to create an instance of notepad, migrate the
_existing_ session to it, and run the exploit from there. This behaviour
didn't seem to be consistent with other local exploits. The changes
include:

* Existing session is now left alone, only used as a proxy.
* New notepad instance has exploit reflectively loaded.
* New notepad instance has payload directly injected.
* Exploit invocation takes the payload address as a parameter.
* A wait is added as the exploit is slow to run (nature of the exploit).
* Payloads are executed on successful exploit.
Comments for WfsDelay, adjustment to injection

I had inteded to add the `WfsDelay` as Meatballs suggested, but for locl
exploits this doesn't appear to work as expected. After speaking to HDM
we've decided to leave the sleep in there and figure out the `WsfDelay`
thing later.

This also includes a slight refactor which puts the payload and the
exploit in the same chunk of allocated memory. Minor optimisation, but
worth it.
Land #2701 - Refactor of `ppr_flatten_rec`

Also [SeeRM #8140]