[Windows] Grok paster templates produce mixed path separators

While correcting the bug #362833 we discovered plenty of mixed paths separators. While correcting the mentionned bug, deploy.ini and debug.ini now only use "Native Path separators" which means \ for Windows and / for real POSIX systems.

zope.conf and zdaemon.conf still contain many "Mixed Path Separators". This works but is ugly and might not work in a future python release or with specific Python implementations (does it work to in IronPython and Jython?)

This is because, on Windows, $${buildout:directory} uses the native path separator but our templates also contain "hard-coded" extensions.

A patch uploaded against the bug #362833 from Roger Erens points us in a very interesting direction.