The former was deprecated with C++14.

According to the C++11 and C++17 standards, both files are identical.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Fix src/ls.cxx to only print unique schemas.
Refactor src/ls.cxx to use src/input/InputPlugin functionality.

Add dynamic enumeration support to curl plugin.

Prepare the transition to std::mutex.

This adds a bit of overhead, but also adds flexibility to the API,
because arbitrary triggers may be invoked from that virtual method
implementation, not just Cond::signal().

The motivation for this is to make the handlers more dynamic, for the
upcoming buffering class utilizing ProxyInputStream.

To be used when a URL gets added.

Only _WIN32 is defined by the compiler, and WIN32 is not standardized
and may be missing.

Closes #169

Maybe this was once a required kludge for Windows, but it's not
anymore.

Eliminate dependency on io_thread_get().

The old struct config_param remains only for top-level string options.

Has been moved to class InputStream long ago.

Replace InputPlugin attributes.

Replaces the method Close().

Add enum InputResult which is a tri-state.  Input plugins may now fail
and just become unavailable.

Decouple some more from GLib.

Replaces GLib's GError.