..plus whitespace cleanup for make check

.. im now going to refactor the tcp request and server tests to utilize
each other, so no more external network ugliness

.. up next: windows!
.. impl'd uv::direct::read_stop() and uv::direct::close() to wrap things up
.. demonstrated sending data out of the uv_read_cb via a channel (which
we block on to recv all of it, complete w/ EOF notification) that is
read from after the loop exits.
.. helpers to read the guts of a uv_buf_t
.. an idea im kicking around: starting to pile up all of these hideous
data accessor functions in uv::direct .. I might make impl/iface pairs
for the various uv_* types that I'm using, in order to encapsulate those
data access functions and, perhaps, make the access look a little cleaner
(it still won't be straight field access, but it'll be a lot better)
.. formatting cleanup to satisfy make check

so we're now adhering the libuv C api and passing structs by-val where
it is expected, instead of pulling pointer trickery (or worse having to
malloc structs in c++ to be passed back to rust and then into C again)

have to use ++ sigil in rust-side extern fn decls in order to have rust
actually copy the struct, by value, onto the C stack. gotcha, indeed.

also adding a helper method to verify/remind how to pass a struct by-val
into C... check out the rust fn sig for rust_uv_ip4_test_verify_port_val()
for more infos

ways to go, still..

.. but passing sockaddr_in by val back to C is broken, still passing by
ptr
.. the uv_write_cb is processed, but we have a status -1.. there is
also valgrind spew.. so buf passing is broken, still.

lots of changes, here.. should've commited sooner.
- added uv::direct module that contains rust fns that map, neatly, to
the libuv c library as much as possible. they operate on ptrs to libuv
structs mapped in rust, as much as possible (there are some notable
exceptions). these uv::direct fns should only take inputs from rust and,
as neccesary, translate them into C-friendly types and then pass to the
C functions. We want to them to return ints, as the libuv functions do,
so we can start tracking status.
- the notable exceptions for structs above is due to ref gh-1402, which
prevents us from passing structs, by value, across the Rust<->C barrier
(they turn to garbage, pretty much). So in the cases where we get back
by-val structs from C (uv_buf_init(), uv_ip4_addr(), uv_err_t in callbacks)
, we're going to use *ctypes::void (or just errnum ints for uv_err_t) until
gh-1402 is resolved.
- using crust functions, in these uv::direct fns, for callbacks from libuv,
will eschew uv_err_t, if possible, in favor a struct int.. if at all
possible (probably isn't.. hm.. i know libuv wants to eventually move to
replace uv_err_t with an int, as well.. so hm).
- started flushing out a big, gnarly test case to exercise the tcp request
side of the uv::direct functions. I'm at the point where, after the
connection is established, we write to the stream... when the writing is
done, we will read from it, then tear the whole thing down.

overall, it turns out that doing "close to the metal" interaction with
c libraries is painful (and more chatty) when orchestrated from rust. My
understanding is that not much, at all, is written in this fashion in the
existant core/std codebase.. malloc'ing in C has been preferred, from what
I've gathered. So we're treading new ground, here!

get_with_default (nee from_maybe) => get_default
with_option (nee maybe) => map_default
with_option_do (nee may) => iter

As per discussion of 21be1379

Closes #1619

Most could use the each method, but because of the hack used to
disambiguate old- and new-style loops, some had to use vec::each.

(This hack will go away soon.)

Issue #1619

Keep their aux builds from stomping on each other

This is not something most people want to be doing and may
be a source of error.

and introduce more indirection where it may be needed

Add len to str extensions