This moves the compatibility include files from include to
include/compat so we can use the awful MS C compiler
<../include/> trick to emulate the GNU #include_next extension.
This also removes a few old compat files we do not need anymore.
The API/ABI for the LibreSSL 2.1.x series is now fixed, so we can safely
enable libtls it by default. This is useful for new OpenNTPD and
OpenSMTPD releases as well.
ok deraadt@ beck@ sthen@
Use './configure --enable-libtls' to build the library and install the
associated manpages. Note that the API and ABI of this library may
change still, though feedback is welcome.
ok deraadt@ jsing@ tedu@