evaluation for faked "." entry.
* mount.cc (fs_info::update): Move setting of is_cdrom after checking
for caseinsensitivity. Recognize UDF in is_cdrom case and set
caseinsensitive flag according to UDF brokenness determined by OS.
Add comment to explain why.
* mount.h (class fs_info): Add is_udf status flag.
* path.cc (symlink_info::check): Add workaround for UDF bug in
terms of casesensitivity on certain OSes.
* wincap.h (wincaps::has_broken_udf): New element.
(wincaps::has_broken_udf): New element
