quic: first code that actually uses ngtcp2

Heavily based on the client.cc ngtcp2 example (there are no API docs
yet), this is my first code dump that has ngtcp2-using code.

There is missing code implementation that prevent this code from even
trying to function. Some of them marked with comments.

lib/Makefile.inc

@@ -55,7 +55,7 @@ LIB_CFILES = file.c timeval.c base64.c hostip.c progress.c formdata.c   \
   curl_multibyte.c hostcheck.c conncache.c pipeline.c dotdot.c          \
   x509asn1.c http2.c smb.c curl_endian.c curl_des.c system_win32.c      \
   mime.c sha256.c setopt.c curl_path.c curl_ctype.c curl_range.c psl.c  \
-  doh.c urlapi.c quic.c
+  doh.c urlapi.c quic.c quic-crypto.c
 
 LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   formdata.h cookie.h http.h sendf.h ftp.h url.h dict.h if2ip.h         \
@@ -75,7 +75,8 @@ LIB_HFILES = arpa_telnet.h netrc.h file.h timeval.h hostip.h progress.h \
   curl_setup_once.h multihandle.h setup-vms.h pipeline.h dotdot.h       \
   x509asn1.h http2.h sigpipe.h smb.h curl_endian.h curl_des.h           \
   curl_printf.h system_win32.h rand.h mime.h curl_sha256.h setopt.h     \
-  curl_path.h curl_ctype.h curl_range.h psl.h doh.h urlapi-int.h quic.h
+  curl_path.h curl_ctype.h curl_range.h psl.h doh.h urlapi-int.h quic.h \
+  quic-crypto.h
 
 LIB_RCFILES = libcurl.rc
 

lib/hostip6.c

@@ -163,7 +163,8 @@ Curl_addrinfo *Curl_getaddrinfo(struct connectdata *conn,
 
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = pf;
-  hints.ai_socktype = conn->socktype;
+  hints.ai_socktype = (conn->transport == TRNSPRT_TCP) ?
+    SOCK_STREAM : SOCK_DGRAM;
 
 #ifndef USE_RESOLVE_ON_IPS
   /*