* autoload.h: Add additional field to autoload block for handling unimplemented
functions.
(LoadDLLfuncEx): New function which accepts additional parameter for
controlling unimplemented function behavior.
(LoadDLLfunc): Use LoadDLLfuncEx.
* dcrt0.cc: Use new arguments for LoadDLLfunc. Add advapi32 routines.
(noload): Rewrite in assembler. Handle new unimplemented function type.
* exceptions.cc: Eliminate another vestige of StackWalk stuff.
* net.cc: Use new arguments for LoadDLLfunc.
* uinfo.cc: Ditto.
* config.h.in: Remove obsolete define.
* path.h (isdrive): New macro.
* dcrt0.cc (globify): Use new macro to determine if a string refers to an
MS-DOS drive.
* environ.cc (winenv): Ditto.
* spawn.cc (find_exec): Ditto.
* path.cc (get_raw_device_number): Ditto.
(mount_info::conv_to_posix_path): Ditto.
(chdir): Ditto.
(cygwin_posix_path_list_p): Ditto.
(cygwin_split_path): Ditto.
(path_conv::check): Move tmp_buf to beginning of function since it can be used
earlier in the loop. Use tmp_buf rather than 'root' to hold root information.
(mount_info::conv_to_win32_path): Add trailing slash to end of mount path when
it translates to a drive. Add defensive code to avoid writing beyond the end
of 'dst'.
