This is consistent with the fact that custom LDFLAGS are already allowed, and
for once, it makes warning options easier to control.

Also use automatic variables $@ and $^ consistently.

1. Have a faster copy of strlcpy()
2. Remove redundant legacy files
3. Fix an issue with NULL check on array name

Diff by Ypnose

The magic.mgc file gets created in the local directory, opening
the global file throws unwanted messages. So we are using the o/p
of the file command to determine if the file is a plain text file.

Use mpv, fmedia, zathura.
Invoke libmagic to identify text files and open with vim.
Use xdg-open for unhandled mimes.