Add disassembly view

[nyxxxie]

We want to be able to display a series of bytes as disassembly (preferably with support for metadata tables, xrefs, and other built in data tables). There should be a view to do this. View should support selecting code, displaying address, bytes, and instructions (with comments), and highlighting. It's reccomended that a custom widget be created similar to the hex editor so that things like flowgraphs can be added later. It's also reccomended that the output of capstone be tokenized for the editor somehow.

For now, just use capstone on an ordinary file containing x86 assembly to test the widget, when #20 and #21 are done we can modify it to use the spade file api.

[nyxxxie]

This will be replaced by bae, closing.