configure.ac some cleanup, refactoring, cosmetics
configure.ac: properly check for epoll support by macro from autoconf archive
configure.ac: change configure flag from '--disable-pipe' to '--enable-soketpair' with additional check options
configure.ac: W32 cleanup
configure.ac: simpler check for SOCK_NONBLOCK and print message for SOCK_NONBLOCK
configure.ac: disable SPDY by default on W32
Update libcurl autoconf macros from upstream
configure.ac: refactoring libcurl tests
rewritten configure tests for OpenSSL, use OpenSSL flags only where required, updated libmicrospdy build flags
configure.ac: update crypt libs detections, use crypt libs flags only where is required
configure.ac: fix test for PostProcessor, basic Auth, digest Auth for "--enable-xx=val" case
configure.ac: add --disable-doc and --disable-examples options
configure.ac: updated tests for zzuf and socat for nice printing results