Multi-Platform Support

[calebstewart]

Is your feature request related to a problem? Please describe.
No.

Describe the solution you'd like
pwncat is currently only a linux post-exploitation tool. I'd like to expand this out to support multiple platforms. This would not only solve the Mac/BSD issues that I've seen sporadically, but also potentially provide Windows support for pwncat.

Describe alternatives you've considered
There aren't many alternatives. Either pwncat supports an abstract/multi-platform environment or it doesn't.

Additional context
This will require a lot of changes within the internals of pwncat. I'm already working on this, and I don't intend for the user-interface to change much at all.

This mainly requires abstracting all interaction with a given target/victim into a single abstract class which handles running process, accessing files, etc. Then providing a platform identifier connected to each session, and ensuring modules/commands specific to a platform are only run on that platform. In the process, I'm removing all the global data structures and moving to a manager model.

Some of the module API will change (e.g. passing sessions as the target of a module invocation). Also, database API will be moved into the session object in order to track sessions better (and hopefully decrease possible database corruption/data loss scenarios).

[trevorbryant]

For anybody that's been tracking, all of this work has been working out of the platform branch.

[calebstewart]

This was resolved by 3f799dd