wl-clipboard requires any file name to be piped in

[jboyens]

When emulating a command like:

xclip -selection clipboard /tmp/filename

it gets translated to:

wl-copy /tmp/filename

Unfortunately, this means that the clipboard now contains literally the text /tmp/filename as wl-clipboard expects files to be piped in.

It should translate the command to:

wl-copy < /tmp/filename