Refactor MemoryView

[joshwatson]

I think that I want to implement Memory as a BinaryView that starts out as a shadow copy of the original BinaryView being used by the Emilator object. This gives us segments, sections, page permissions, reading/writing, and probably more for free. The only complication would then be adding new memory segments, which would mean having to deal with mappings, but even that shouldn't be an issue.