Found with llvm-namespace-comment
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with readability-avoid-const-params-in-decls
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with modernize-redundant-void-arg
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Found with readability-simplify-boolean-expr
Signed-off-by: Rosen Penev <rosenp@gmail.com>

Split several printf() calls to make it easier to deal with all those
#ifdefs.

So long, autotools!  This is my last MPD related project to migrate
away from it.  It has its strengths, but also very obvious weaknesses
and weirdnesses.  Today, many of its quirks are not needed anymore,
and are cumbersome and slow.  Now welcome our new Meson overlords!

Modeled after std::filesystem::operator/() from C++17.

To get udisks2 support started, this commit contains the configure.ac
option and a "neighbor" plugin which shows block devices.  Later, this
will allow mounting removable media with a new storage plugin.

From https://github.com/CM4all/libcommon/commit/a7cef404c1f7eedff1a629da48f77491218ee281

To be used by upcoming code.

These have no use, exception for creating an artificial dependency
from input_plugins[] to all archive plugins.

Prepare for option values.

Allow the caller to use a simple "for" loop without checking
arguments.

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

Closes #169

Use wchar_t for everything on Windows.  Solves a lot of filesystem
charset problems.