It's necessary to return the actual filename with correct casing and a
plain stat doesn't allow that. Make read_directory_stat() return the
result of the stat() call on a case-insensitive filesystem only when the
file is missing.

When searching for a specific filename on a case-insensitive filesystem
we first try with stat(). If stat() does find the file we currently
return the requested filename back.

That presents an issue when the application cares about the casing of the
actual file stored on-disk. Specifically, NtQueryDirectoryFile is
supposed to return the actual filename with correct casing.

One possible solution to the issue, without having to resort to manually
scanning the directory entries, is to make use of the OS X getattrlist()
function, since it can return the filename stored on the filesystem.

This just falls back to doing the same as GetSystemTimeAsFileTime.

This also fixes the layout code for the BTNS_WHOLEDROPDOWN case.

The toolbar need not be the same width as the parent.

It's only set and used by a single function.

Some popular ALSA plugins claim support for a large number of channels
because they have the capability to mix that down to the actual hardware
configuration.

Instead of defaulting to 5.1 Surround sound for these plugins, let's
fall back on the much more common Stereo configuration.  Users with
actual 5.1 Surround setups can tell us about it in winecfg.

Also, send WM_NOTIFY mesages when collapsing the previous selection and
expanding the new one.