configure.ac: update macros format, use AX_CHECK_COMPILE_FLAG instead of custom test
Update libgcrypt autoconf macros from upstream
Updated m4/libgcrypt.m4 to use $SED and $GREP instead of hardcoded names
Update libcurl autoconf macros from upstream
autoconfigure.ac cleanup
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 cosmetics
configure.ac: W32 cleanup
configure.ac: add message for SOCK_NONBLOCK
configure.ac refactoring
configure.ac: simpler check for SOCK_NONBLOCK
configure.ac: disable SPDY by default on W32
configure.ac: refactoring libcurl tests
rewritten configure tests for OpenSSL, use OpenSSL flags only where required, updated libmicrospdy build flags