Add ManualMap support

[CasualX]

Adds an extension method mmap(self) on all 'a, P: Pe<'a> + Copy which will manually map the module and prepare it for execution.

The scope of this PR is to prepare a DLL image for execution inside the calling process (no DLL injection).

[CasualX]

TLS support is iffy, the tests are crashing when trying to call a method from the demo dll.

The code from Dummy64.dll, annotated, is

; int __cdecl fnPasswdsBypass(void)
; Load the tls index
mov         ecx,dword ptr [__tls_index]
; Load the ThreadLocalStoragePointer from the TEB
mov         rax,qword ptr gs:[58h]
mov         edx,1
; Load the TLS pointer for our module, here it goes wrong and returns garbage
; If you look at TlsSetValue in KernelBase.dll you see it saved the tls pointer to
; 	mov         qword ptr [rdi+rbx*8+1480h],rdx
; Note the offset of 0x1480 and lacking offset in demo code
mov         rax,qword ptr [rax+rcx*8]
mov         byte ptr [rdx+rax],1
mov         eax,2Ah
ret

I compiled the demo on Windows 7 before I upgraded to Windows 10 maybe that has something to do with this? Idk.

[chtotut]

Is this PR proof of concept only?
Do you plan to add this functionality to the library?

[CasualX]

In its current state it is a proof of concept:

• I remain undecided on the API
• TLS issues (see above) that I am unable to solve in a satisfying manner without hacking it with inline assembly
• I am mainly motivated by my own use cases and I haven't had a need for manual mapping recently

I don't foresee this changing any time soon.