Split the string into path segments with StringView::Split().  This
prepares to eliminate all allocations from the method.

The former is deprecated by C++14. It's also functionally the same.

From the standard:

19.4
The header<cerrno>is described in Table 43. Its contents are the same as
the POSIX header<errno.h>,except that errno shall be defined as a macro.
[Note: The intent is to remain in close alignment with the POSIX
standard.] A separate errno value shall be provided for each thread.
Signed-off-by: Rosen Penev <rosenp@gmail.com>

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>

Merge some duplicate code in a central library.

Add a runtime sanity check to avoid the assertion failure.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/660

This attribute is not a URI; it is just the filename without its
parent directory path.  To avoid confusion, let's rename it to
"filename", leaving the struct without a "uri" attribute.

No longer allocate it as a "VarSize".  This used to be a clever trick
to save memory 10 years ago, but these days, keeping the code
maintainable seems more important than saving a few kilobytes of
memory.

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.

Supports .mpdignore on NFS/SMB and others (closes #290).

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

Closes #169

Signed-off-by: FlashSystems <developer@flashsystems.de>

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.