Update curl and use mbedtls instead of openssl.

contrib/curl/include/Makefile.am

@@ -0,0 +1,5 @@
+SUBDIRS = curl
+
+EXTRA_DIST = README
+
+AUTOMAKE_OPTIONS = foreign no-dependencies

contrib/curl/include/curl/.gitignore

@@ -0,0 +1,4 @@
+curlbuild.h
+curlver.h.dist
+stamp-h2
+stamp-h3

contrib/curl/include/curl/Makefile.am

@@ -0,0 +1,53 @@
+#***************************************************************************
+#                                  _   _ ____  _
+#  Project                     ___| | | |  _ \| |
+#                             / __| | | | |_) | |
+#                            | (__| |_| |  _ <| |___
+#                             \___|\___/|_| \_\_____|
+#
+# Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
+#
+# This software is licensed as described in the file COPYING, which
+# you should have received as part of this distribution. The terms
+# are also available at https://curl.haxx.se/docs/copyright.html.
+#
+# You may opt to use, copy, modify, merge, publish, distribute and/or sell
+# copies of the Software, and permit persons to whom the Software is
+# furnished to do so, under the terms of the COPYING file.
+#
+# This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+# KIND, either express or implied.
+#
+###########################################################################
+pkginclude_HEADERS = \
+	curl.h curlver.h easy.h mprintf.h stdcheaders.h multi.h \
+	typecheck-gcc.h curlbuild.h curlrules.h
+
+pkgincludedir= $(includedir)/curl
+
+# curlbuild.h does not exist in the git tree. When the original libcurl
+# source code distribution archive file is created, curlbuild.h.dist is
+# renamed to curlbuild.h and included in the tarball so that it can be
+# used directly on non-configure systems.
+#
+# The distributed curlbuild.h will be overwritten on configure systems
+# when the configure script runs, with one that is suitable and specific
+# to the library being configured and built.
+#
+# curlbuild.h.in is the distributed template file from which the configure
+# script creates curlbuild.h at library configuration time, overwiting the
+# one included in the distribution archive.
+#
+# curlbuild.h.dist is not included in the source code distribution archive.
+
+EXTRA_DIST = curlbuild.h.in
+
+DISTCLEANFILES = curlbuild.h
+
+checksrc:
+	@@PERL@ $(top_srcdir)/lib/checksrc.pl -Wcurlbuild.h -D$(top_srcdir)/include/curl $(pkginclude_HEADERS) $(EXTRA_DIST)
+
+if CURLDEBUG
+# for debug builds, we scan the sources on all regular make invokes
+all-local: checksrc
+endif