'RELENG_4_1_0_RELEASE'.

This commit was manufactured to restore the state of the 4.1-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

Approved by:	jkh

Currently only supported for ftp connections.

Brucify the Makefile.
Differentiate atime and mtime in fetch*Stat().
Fix a few pointer bugs.
Tweak some error messages.
Don't #include sys/param.h and stdio.h in fetch.h.
Document that sys/param.h and stdio.h must be #included before fetch.h.

This commit introduces the following features:

 a) the fetchStat*() functions, which return meta-information for a
    document, such as size, modification time, etc.

 b) the use of the com_err(3) facilities to report errors.

It also fixes a bunch of style bugs and a few logic bugs and somewhat
improves the man page.

Changed files, in alphabetical order:

 Makefile:
  Don't generate macros in {ftp,http}err.c.

  Generate category fields for the error message lists.

  Compile the error table.

  Install fetch_err.h along with fetch.h.

 common.c:
  Remove the _netdb_errstring() macro, and add FETCH_ERR_NETDB to the
  error code in the _netdb_seterr() macro.

  Add categories to the _netdb_errlist table.

  Report errors through the Common Error library.

 common.h:
  Add the DEBUG macros.

  Add prototype for fetchConnect().

  Remove the prototype for _fetch_errstring(), which is local to common.c

  Add a categroy field to struct fetcherr, and define constants for
  error categories.

  Define macros for _{url,netdb,ftp,http}_seterr().

 errors.et: (new file)
  List error categories.

 fetch.3:
  Document the fetchStat*() functions.

  Move the "unimplemented functionality" comments from NOTES to BUGS.

  Document that applications which use libfetch must also use
  libcom_err, and list existing error codes.

  Undocument fetchLastErr{Code,String}.

  Remove the (empty) DIAGNOSTICS section.

  Mention Eugene Skepner in the AUTHORS section.

 fetch.c:
  Move the DEBUG macros to common.c

  Add fetchStat() and fetchStatURL().

  Generate error messages for URL parser errors, and fix a minor bug
  in the parser.

  Use 'struct url' instead of 'url_t'.

  Remove fetchLastErr{Code,String}.

 fetch.h:
  Use 'struct url' instead of 'url_t', and remove the typedef.

  Define struct url_stat (used by fetchStat()).

  Add prototypes for fetchStat*().

  Remove the declarations for fetchLastErr{Code,String}.

  Include fetch_err.h.

 fetch_err.et: (new file)
  Error table for libfetch.

 file.c:
  Add fetchStatFile().

  Use 'struct url' instead of 'url_t'.

 ftp.c:
  Add fetchStatFTP().

  Use 'struct url' instead of 'url_t'.

  Don't use fetchLastErrCode.

 ftp.errors:
  Add categories to all error messages.

 http.c:
  Add fetchStatHTTP().

  Use 'struct url' instead of 'url_t'.

  Don't use fetchLastErr{Code,Text}.

 http.errors:
  Add categories to all error messages.

Prompted by: jkh and Eugene Skepner
Numerous sugestions from: Garett Wollman and Eugene Skepner

alphabetical order:

 Makefile:
  Add common.c to SRCS.

  Make debugging easier by making 'CFLAGS += -DNDEBUG' conditional on DEBUG

  Don't declare struct {ftp,http}err in {ftp,http}err.c; use struct fetcherr
  instead.

 README:
  Remove the todo list, which is out of date anyway.

 common.c: (new file)
  Gather utility functions in this file.

  Merge the error reporting functions intp _fetch_errstring(),
  _fetch_seterr() and _fetch_syserr().

  Set fetchLastErrCode and fetchLastErrText appropriately when fetchConnect
  fails.

 common.h: (new file)
  Gather internal prototypes and structures in this files.

 fetch.3:
  Undocument fetchFreeURL().

  Document a few more known bugs.

  Document fetchLastErrCode and fetchLastErrText.

 fetch.c:
  Add descriptive comments to all functions that lacked them.

  Move fetchConnect() to common.c.

  Obviate the need for fetchFreeURL(), and remove it.

 fetch.h:
  Modify struct url_t so the document part is at the end.

 ftp.c:
  Remove code that is duplicated elsewhere.

 http.c:
  Remove code that is duplicated elsewhere.

Prompted by: jkh