Add virtual mount point support for collective.recipe.filestorage

[Jean Jordaan]

Zope allows mounting multiple storages into one ZODB.
Configuration of the mount point is done with the 'mount-point' directive in 'zope.conf'.
The full syntax of this directive is poorly documented. For the whole story, see Zope2/Startup/datatypes.py
I've added support for this syntax in the attached patch.
However, before getting all excited, have a look at https://bugs.launchpad.net/zope2/+bug/143144

[Jean Jordaan (jean-jordaan)]

New patch, prevents https://bugs.launchpad.net/collective.buildout/+bug/409296 ..

[Jean Jordaan (jean-jordaan)]

Sorry, the URL should be https://bugs.launchpad.net/zope2/+bug/143144/comments/9

[Jean Jordaan (jean-jordaan)]

Reworked patch, based on comments. Also fixes the signature of _subpart_option.

[Michael Hierweck (hierweck)]

collective.filestorage handles the defintion of filestorages more flexible than plone.recipe.zope2zeoserver/zope2instance do.

Can't we merge collective.filestorage into plone.recipe.zope2zeoserver/zope2instance so that is supports multiple filestorages out of the box?

Alternative: Can't we add an option (e.g. dont-gen-storage = true) to plone.recipe.zope2zeoserver/zope2instance so that is does not define any storages at all. All storages could be defined either using collective.filestorage or zope/zeo-conf-addtional then.