* fhandler.cc (fhandler_base::fork_fixup): Don't protect handle.

* fhandler.cc (fhandler_base::fork_fixup): Don't protect handle.
* dlfcn.cc: Fix to confirm to coding standards.  Reorganize includes throughout
to accomodate new cygheap.h usage.
* cygheap.h (cygheap_fdmanip): New class: simplifies locking and retrieval of
fds from cygheap->fdtab.
(cygheap_fdget): Ditto.
(cygheap_fdnew): Ditto.
* fcntl.cc (_fcntl): Use new method to lock fdtab and retrieve info.
* ioctl.cc (ioctl): Ditto.
* mmap.cc (mmap): Ditto.
* net.cc: Ditto, throughout.
* passwd.cc (getpass): Ditto.
* path.cc (fchdir): Ditto.
* pipe.cc (make_pipe): Ditto.
* sec_acl.cc (facl): Ditto.
* syscalls.cc: Ditto, throughout.
* termios.cc: Ditto, throughout.