* winsup.h (NT_MAX_PATH): Revert ill-advised change to 32767.

	* winsup.h (NT_MAX_PATH): Revert ill-advised change to 32767.
	Accommodate change throughout.

	* cygwin.din (cygwin_conv_path): Export.
	(cygwin_conv_path_list): Export.
	(cygwin_create_path): Export.
	* dcrt0.cc (dll_crt0_1): Use cygwin_conv_path.
	* dtable.cc (handle_to_fn): Ditto.  Don't expect UNICODE_STRING being
	0-terminated.
	* environ.cc (env_plist_to_posix): New helper function.
	(env_plist_to_win32): Ditto.
	(env_path_to_posix): Ditto.
	(env_path_to_win32): Ditto.
	(return_MAX_PATH): Remove.
	(conv_envvars): Use new helper functions.  Drop removed members.
	(win_env::operator =): Accommodate removal of path length functions.
	(win_env::add_cache): Accommodate new env helper function API.
	(posify): Ditto.
	* environ.h (struct win_env): Ditto. Remove path length function
	pointers since they are unused.
	* path.cc (warn_msdos): Use cygwin_conv_path.
	(getfileattr): Use new tmp_pathbuf::u_get method.
	(fillout_mntent): Ditto.
	(symlink_info::check): Ditto.
	(path_conv::check): Use sizeof (WCHAR) instead of constant 2.
	(symlink_info::check_reparse_point): Ditto.
	(conv_path_list): Get max size of target string as argument.  Call
	cygwin_conv_path as helper function.
	(cygwin_conv_path): New function.
	(cygwin_create_path): New function.
	(cygwin_conv_to_win32_path): Just call cygwin_conv_path with size set
	to MAX_PATH.
	(cygwin_conv_to_full_win32_path): Ditto.
	(cygwin_conv_to_posix_path): Ditto.
	(cygwin_conv_to_full_posix_path): Ditto.
	(conv_path_list_buf_size): Add FIXME comment.
	(env_PATH_to_posix): Rename from env_win32_to_posix_path_list.
	Add size argument as required for env helper functions.
	(cygwin_win32_to_posix_path_list): Call conv_path_list with size set to
	MAX_PATH.
	(cygwin_posix_to_win32_path_list): Ditto.
	(cygwin_conv_path_list): New function.
	(cwdstuff::get): Fix length argument in call to sys_wcstombs.
	* spawn.cc (find_exec): Use cygwin_conv_path_list.
	* tls_pbuf.h (tmp_pathbuf::u_get: New method.
	* uinfo.cc (cygheap_user::ontherange): Allocate temporary path buffers
	using tmp_pathbuf.  Use cygwin_conv_path.
	* winf.cc (av::unshift): Use cygwin_conv_path.
	* include/cygwin/version.h: Bump API minor number.
	* include/sys/cygwin.h: Comment out old cygwin32_XXX API.
	Mark old path handling API as deprecated.
	(cygwin_conv_path_t): Typedef.  Define values.
	(cygwin_conv_path): Declare.
	(cygwin_create_path): Declare.
	(cygwin_conv_path_list): Declare.