Revert to old style path.

- Incrementing didn't work properly when extending multiple files.
  https://bugs.launchpad.net/zc.buildout/+bug/421022

windows, urllib raises an invalid ioerror.

windows, urllib raises an invalid ioerror.

  The standard Python -m option didn't work for custom interpreters.

  Scripts run using generated interpreters didn't have __file__ set correctly.

  Scripts generated with relative-paths eanbled couldn't be
  symbolocally linked to other locations and still work.

  Option incrementing and decrementing didn't work for options
  specified on the command line.

No commit message

(Also stop writing doc.txt. --long-description is better. And
rearranged setup.py a little.)

- When doing variable substitutions, you can omit the section name to
  refer to a variable in the same section (e.g. ${:foo}).

- When doing variable substitution, you can use the special option,
  ``_buildout_section_name_`` to get the section name.  This is most handy
  for getting the current section name (e.g. ${:_buildout_section_name_}).

- A new special option, ``<`` allows sections to be used as macros.

refer to a variable in the same section (e.g. ${:foo}).

When doing variable substitution, you can use the special option,
``_buildout_section_name_`` to get the section name.  This is most handy
for getting the current section name (e.g. ${:_buildout_section_name_}.

(Also removed some extra imports and made formatting changes.)

does it for easy-install:

- require the download cache (but not namespace directories) to be an
  existing directory in order to catch configuration bugs

- made relative download cache paths refer to the buildout directory

  path and a flag indicating whether the downloaded copy is a temporary file
- use this flag to clean up temporary files both when downloading extended
  configuration files and in the tests

Conflicts:
	CHANGES.txt
	src/zc/buildout/buildout.py

  could be inserted into sys.path if a relative path was used to run
  the generated script.