simplify main function

move command line parsing logic into its own module

refactor command functions into a commands namespace

refactor error types into an errors module

use BufReader instead of direct File interface

minor fixes for revlog parser

Add a bare-bones hg status implementation

use structopt instead of clap

match on subcommand names

typo fix

rework error handling a bit

match on subcommands

refactor to use snafu

move content and header into entry module

refactor revlogs into submodules for content, headers, and entries

refactor revlog-handling code into a revlogs module

move everything to the root of the repo

make pretty-printing revlog content try to interpret as utf-8 and if that fails display as ascii-escaped text

remove debug print

panic if we're handed a non-inline revlog5~