bring in newer ev and bufio from telescope merge our local changes to bufio though.

amused-web: avoid an (im)possible write out-of-bounds in buf_write spotted while bringing syncparty' bufio.[ch] in sync; if the requested len could be bigger than buf->len plus the buf_grow() increment, so we have to iterate. This is currently impossible since we're usign buf_write() only to add one byte.

amused-web: parse POST data in bufio' rbuf Add a proper upper limit (4096 seems enough for now) and safely NUL-terminate the rbuf. The idea is to later drop the clt->buf static buffer and allocate it on demand only when we need to do (http) chunking.

amused-web: first round of portability tweaks We still need an implementation of SHA1Init() & co, which on linux is not in libc (but is available with the same APIs in libmd.)

amused-web: tweak bufio APIs for future HTTP usage add bufio_free() to free the bufio without re-initialization, add support for writing HTTP-style chunks and add ability to extract data from the read buffer via the bufio_* layer instead of peeking at the internals.

amused-web: remove the TLS handling from bufio

amused-web: import bufio.[ch] from syncparty