Build system update

From: David Abrahams (david.abrahams_at_[hidden])
Date: 2001-10-06 13:39:21

I've made some build system improvements. regex, threads, and python will
all build from the top level. If you build the 'test' target from the top
level, it will run all regressions.

Nothing in the project depends on the version of jam checked in on the
jam_src branch, yet. I will be sure to post an executable and sources in the
files area when that happens.

-Dave

---------

Jamfile:
  subincludes for thread, python libs, and status for regression tests

Jamrules:
  Use the new path-global rule to establish BOOST_ROOT correctly for all
subprojects

libs/regex/build/Jamfile
  Take advantage of correct BOOST_ROOT setting

libs/python/build/Jamfile
  Search for python executable; don't try to build anything if it can't be
found.
  don't build tests by default
  improved comments, organization, and naming.

status/Jamfile
  Fixed references to config test files
  Failed tests now leave their stdout results in <testname>.error instead of
removing it
  No test targets are dependencies of 'all' anymore
  Added comments
  Reorganized

tools/build/Jambase
  Meant to check this in long ago.

tools/build/allyourbase.jam
  Fixed SHELL_EXPORT setting, added SHELL_SET
  removed 'test' from the dependencies of 'all'; tests no longer run by
default.
  Fixed the direction of slashes for Windows when ALL_LOCATE_TARGET is used.
  Added path-global rule for declaring path variables which may be relative
  rule in-invocation-subdir returns true if the current subproject is the
one
     from which Jam was invoked
  rule protect-subdir is now used to protect subproject variables
  rule tokens-to-simple-path converts path tokens to a simplified path.

tools/build/boost-base.jam
  Fixed bugs

tools/build/jam_src/makedebugjam.bat
  Fixed a bug which prevented a final debug build

tools/build/jam_src/search.c
  Fixed a bug of mine which caused LOCATE to be ignored (!).

===================================================
  David Abrahams, C++ library designer for hire
 resume: http://users.rcn.com/abrahams/resume.html

        C++ Booster (http://www.boost.org)
          email: david.abrahams_at_[hidden]
===================================================