Added configPersist

[NotoriousRebel]

Added a modified version of ConfigPersist.
What this does:

1. Create a keyfile
2. Invoke C# compiler to compile assembly with C# payload of user's choice
   Compilation also signs the assembly with keyfile
3. Install assembly onto Global Assembly Cache (GAC)
4. Modify machine.config's runtime appDomainType and appDomainManagerAssembly elements to point to our assembly installed onto the GAC.

TODO

• Add testing