aio: 1st stub libuv bindings
more aio work, init_loop, tcp_connect, test
add more docs
aio: more callback work
add PN_IS_FFIPTR (foreign ptr)
aio: tcp_connect6,pipe_open,pipe_bind,pipe_connect,stream_write
aio: udp_open,udp_bind,udp_bind6,udp_getsockname
aio: more methods, provide larger aio_ wrapper structs passed around

add P and cl to our aio_T_s structs, for callbacks.
aio: init methods called in constructor, removed
add more callbacks, do not create a new cb request/handle, reuse it
make EXTLIBS optional, depend on the library
test aio_tcp_new, stricter loop type check
aio: fix loop, add aio_last_error
aio: probe for libuv and pcre and copy it into lib/ if needed
fix static targets: libs
aio: fix more loop inits
aio: move loop to the end, make it an aio_loop object

and add mode globals: aio_run modes, aio_version, aio_version_string
aio: add run, more aio_last_error's
aio: more typechecks, more aio error handling
aio: couple of more methods. tty, pipe, stream, prepare, check, shutdown