do not just see if it's there, make sure it is usable. Currently, alpine sys/tree.h generates code that doesn't work with both gcc and clang (for different reasons!) so make sure we can actually use it, or fall back on the bundled version.

FreeBSD and NetBSD have sys/endian.h, on MacOS we need to use the functions from libkern/OSByteOrder.h see github issue #1

reported by @Et7f3 in github issue #1, thanks!

* fix twstat handling of mode bits * rejects incoming connections with a ridiculously small msize * allow "jumbo" (i.e. more than 16K) Twrite and Treads * allow Tread to read exactly msize bytes * kamiftp: fix reads wrt msize * kamiftp: do maximum reads and writes

kamiproxy is a TLS-capable proxy that forwards the traffic it gets over plaintext 9p on a local port to a remote 9p server. It uses (and mandates) tls client certificates.

it's not so useful here and not (directly) used anywhere else.

while here also delete the two remaining makefiles from before the -portable merge.

I talked too fast. There's a typo that disabled readline even if found with pkg-config, and also the way I hooked it in kamiftp was wrong...