comment.
* mount.cc (mount_info::from_fstab): Use tmp_pathbuf rather than
stack for big local buffer.
* net.cc (cygwin_gethostname): Call GetComputerNameExA rather than
GetComputerNameA if gethostname failed.
* shared.cc (user_info::initialize): Fix formatting.
* include/sys/file.h: Define flock and accompanying macros if not
already defined in sys/_default_fcntl.h.