(linetest) fix off by one error

This has been here for a while: the "move to column" escape code is
supposed to be zero-based, but empirically that does not seem to be the
case on the several terminal emulators I've tested. (i.e. col(0) and
col(1) are equivalent operations.)

We can remove the erroneous padding from the relative position we
compute, pass it to "move to row and column," and it does what you
would expect.

(deps) fix issue w/ compiling smolboi

This is very strange: `smolboi` was able to be compiled when invoking
`cargo build` at the workspace root, but not from within its own member
root. The issue is that `AsyncReadExt` and `AsyncWriteExt` were not
being resolved. To compound the strangeness: `rusct-analyzer` in my
editor (a) did not show that `use` line as an error, and even helped
auto-complete it.

The issue, it turns out, is that in the latest version fo `futures-util`
has these traits behind a feature flag. I am not sure why that feature
flag seems to have no effect on the workspace root, but here we are.

remove erroneous lock files from workspace members

Merge branch 'feature/rustfmt-spaces'

(rust2018) (style) replace #[macro_use] for log crate

(style) add editorconfig file

(style) (rustfmt) run rustfmt on crate

(rust2018) recursion limit no longer needed?

(release) smolboi v0.1.1

* Merge branch 'feature/smol-1.0'
  * Create new single threaded executor
    * Update TCP acceptor task to use that executor
    * Update event broker task to use that executor

 * Use `smol::block_on` in runtime thread

(deps) update to smol 1.x

(bump version) update smolboi & linetest to rust 2021

(rustup) unlock dependencies for latest rustc

(repo) update readme to mention linetest crate

(repo) Release project under BSD license.

(ui/buffer): fix panic when using home/end keys

Home needs to update the position of `end` to be consistent w/ the
currently rendered span length, otherwise subtractions involving the end
of the span will underflow.

End likewise needs to update not just the cursor position, but also the
start and end of the current span. Otherwise the cursor will be
inserting text into a span that is rendered off-screen.

(net): add tests for client state machine

- brings in `sluice` crate to create an in-memory bidirectional
  stream which we can use to model a fake TCP connection.

- adds tests surrounding the initial client/server registration
  handshake.

(crate) use `Into` trait where possible

removes `as` for infallible casts. a little gross in a few places
where it requires additional `let` bindings because inference
falls down.

remaining casts are guarded w/ `assert!` as a means to declare
my intent that these *should not* fail in practice, even though they
might in some super future, where you have a 65636p display.

("This software doesn't work on my 65K display! D:" - what a nice problem
that'd be to solve. lol.)

(ui): implement Home & End keys

- (term) adds event handlers for `KeyCode::Home` and `KeyCode::End`.
- (buffer) adds `goto_head` and `goto_tail` methods for `InputBuffer`.

(linetest/ui/buffer): reconcile interaction of resizing w/ pager logic.

This commit implements some changes to the pager which allow it to track
the line index which created the multiline span. We can use this
information to determine which line is currently drawn at the top of
the buffer's viewport.

If the span at the top of the viewport is not the first line in
the buffer then we allow the user to continue scrolling up. Likewise if
the span at the bottom of the viewport is not the last line we allow
them to scroll down.

In the special case where the user resizes their terminal to display
more rows _while at the top of the buffer_ we fill the new rows with
additional lines from the buffer.

(linetest/net) fix issue w/ malformed packets

- Currently malformed packets will termiante the decoder. The protocol is,
  at present, not robust enough to continue following loss of sync. This decision
  may be revisited later if the protocol ever grows some packet framing.

- Added a `quit` channel to allow packet decoding task failure to cascade into
  the main event loop itself.