-fix for 1 attribute only

This code looks for the __error_log__ attribute in order to report an
error.  If it finds no such attribute, it reports the error in a
different way.  Unfortunately, the alternative branch was reporting
the exception that just happened to occur most recently, which is
irrelevant; it needs to report the error that was passed to it.
Fixed.

Please make all future changes on the Zope-2_7-branch instead.

imports Python.h.

- minor cleanups

- separate two tests that were performed in the same test method
- normalize whitespace

a string. This then breaks when you do a Find. Force it to be a string.
Will backport to the 2.7 branch - it should probably go into the 2.6
branch too, but I'll let someone at ZC make that call. (mmm endless beta
cycle :)

to account for changes to mkzopeinstance which make a distinction.

Use the nt_svcutils package instead of the older Zope.Startup.nt package.

in both space and semicolon separated lists

- hoping it will become a standard tool as
  available with each Zope

the nt service utilities within ZEO and ZRS).

- move shared text for warnings so it isn't repeated

- test_path(): make this test pass; the "path" configuration field
  requires that the paths actually exist

the pyexpat module.

Document path and environment directives.

Implement new "environment" section in config file which allows the
setting of environment variables within the configuration file.

Implement new "path" section in config file which allows insertions into
the Python module search path within the configuration file.

Fix bug where $INSTANCE/Products was not inserted into the products
path by default.

Note that most of these changes are for more comprehensive Windows service
support.  Windows can't run a batch file as a service, and sometimes it
is necessary to both munge the python module search path and environment
at startup time.  Instead of writing an executable application to do this,
we rely on the configuration machinery.