#609 Rewrite tools to work at a higher level of abstraction

[Joseph Koshy]

Rewrite our tools (i.e. nm, addr2line, etc) to work at a higher layer of abstraction (e.g. change nm to work with 'lists of program symbols' ), while deferring the details of building these data structures to a lower-level implementation which would be file format specific.

This change would allow use to 'port' our utilities to other file formats holding machine information.

See also: [#578].