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.

Import TemporaryStorage files from the new tempstorage package.

(see related checkin for the tempstorage module in lib/python for rationale).

contains files related to the TemporaryStorage ZODB storage.

These files used to be in the TemporaryFolder Product, but have been
moved to solve issues which resulted from premature imports during startup
caused by import of the TemporaryFolder package
by the configuration machinery (particularly the premature import of
Globals, which pulls in almost every Zope package) during database setup.

     - PathIndex and TopicIndex are now using a counter for the number
       of indexed objects instead of using a very expensive calculation
       based on the keys of their indexes.

Allow for a different skelsrc directory at install time.

an ExtensionClass type that get into this code can raise RuntimeWarning
under Python 2.3, because the comparison result may be outside the
set {-1, 0, 1}.  Worse, on a box where sizeof(ptrdiff_t) > sizeof(int)
(all 64-bit platforms), comparison results across a set of objects
could be inconsistent because the implicit cast of pointer subtraction
to int loses the information-carrying sign bit.

backport of TAL fixes from z3

- i18n and metal interactions

- fix handling of nested translations with tal:content/replace and i18n:name

some reformatting to ease comparisons between 2.x and 3

!!! There is still one problem left: I could not find a page matching
the old http://www.zope.org/SiteIndex/searchForm on the new site !!!

- shipping docutils with optparse/textwrap from Python 2.3 to avoid
  major changes to the docutils code

Be more careful about specifying a container class: root databases should not have a container class.

to an object but returns the name instead of the object (for values
that should be strings that later resolve to an object during startup).

Fix container-class functionality.  It could be specified in the configuration
but was never actually used.

Alias the SimpleTemporaryContainer at the package level.

- Use autoClassFactory by default.  This is better for mounted databases
  than the default.

- Don't specify a default connection class; let the database decide the
  default.

- Allow database types other than zodb_db.

Also set the connection class only when specified.

Changes:

 - startup log handler now pays attention to the logging levels of
   the handlers defined within the config file and uses the "lowest"
   level to log messages to stdout during startup.

 - entirely removed warning when the starting user's umask is "too
   permissive".  it wasn't clear that it added any value under normal
   operations.

 - replaced ancient setuid code with code stolen from zdaemon that
   works the same but looks nicer.

Don't try to optimize by checking for disabled and effective levels within the log method.  The logger's level may not be meaningful if this logger is configured with handlers that accept messages at a lower level than that of the logger itself.

DeprecationWarnings in Python 2.3 go away. See
http://www.python.org/peps/pep-0263.html for more information.