Eliminates a number of allocations, because callers don't need to copy
the strings to a newly allocated buffer only to null-terminate them.
And most callers don't need to have a null-terminated string.

Closes #471

Since we switched from autotools to Meson in commit
94592c14, we don't need to include
`config.h` early to properly enable large file support.  Meson passes
the required macros on the compiler command line instead of defining
them in `config.h`.

This means we can include `config.h` at any time, whenever we want to
check its macros, and there are no ordering constraints.

The "tagtypes" command now has several sub commands which can be used
to edit that mask.

Add one method that prints only the tag values, but not the song
duration.

Enables using range-based "for".

Detach the Song class completely from the public API, only to be used
by SimpleDatabase and the update thread.

Don't create a temporary Song object in handle_lsinfo().  Instead,
print all tags while parsing the remote file.

Move to TagSettings.c and use C99 initializers.

After we've been hit by Large File Support problems several times in
the past week (which only occur on 32 bit platforms, which I don't
have), this is yet another attempt to fix the issue.

This updates the copyright header to all be the same, which is
pretty much an update of where to mail request for a copy of the GPL
and the years of the MPD project. This also puts all committers under
'The Music Player Project' umbrella. These entries should go
individually in the AUTHORS file, for consistancy.

Renamed functions and variables.

Renamed numOfItems to num_items.