* autoload.cc (GetSecurityInfo): Define new autoload function.

* autoload.cc (GetSecurityInfo): Define new autoload function.
(RegQueryInfoKeyA): Ditto.
* fhandler.h (fhandler_virtual::fill_filebuf): Change return type to bool.
(fhandler_proc::fill_filebuf): Ditto.
(fhandler_registry::fill_filebuf): Ditto.
(fhandler_process::fill_filebuf): Ditto.
(fhandler_registry::value_name): Add new member.
(fhandler_registry::close): Add new method.
(fhandler_process::p): Remove member.
* fhandler_proc.cc (fhandler_proc::open): Add set_nohandle after calling
superclass method.  Check return value of fill_filebuf.
(fhandler_proc::fill_filebuf): Change return type to bool.  Add return
statement.
* fhandler_process.cc (fhandler_process::open): Add set_nohandle after calling
superclass method.  Remove references to p.  Check return value of
fill_filebuf.
(fhandler_process::fill_filebuf): Change return type to bool.  Don't use
dereference operator on p.  Add return statement.
(fhandler_process::format_process_stat): Fix typo.
* fhandler_registry.cc: Add static open_key declaration.
(fhandler_registry::exists): Assume path is already normalised.  Try opening
the path as a key in its own right first, before reverting to enumerating
subkeys and values of the parent key.
(fhandler_registry::fstat): Add additional code to return more relevant
information about the registry key/value.
(fhandler_registry::readdir): Explicitly set desired access when opening
registry key.  Remove output of buf from debug_printf format string.
(fhandler_registry::open): Use set_io_handle to store registry key handle.  Set
value_name member.  Move code to read a value from the registry to
fill_filebuf.  Add call to fill_filebuf.
(fhandler_registry::close): New method.
(fhandler_registry::fill_filebuf): Change return type to bool.  Add code to
read a value from registry.
(fhandler_registry::open_key): Make function static.  Use KEY_READ as desired
access unless this is the last path component.  Check the return value of
RegOpenKeyEx for an error instead of hKey.
* fhandler_virtual.cc (fhandler_virtual::lseek): Check the return value of
fill_filebuf.
(fhandler_virtual::open): Remove call to set_nohandle.
(fhandler_virtual::fill_filebuf): Change return type to bool.  Add return
statement.
* security.cc (get_nt_object_attribute): New function.
(get_object_attribute): New function.
* security.h (get_object_attribute): New function declaration.