client: Fix URI scheme to move credentials out of query

• Move ca/cert/key out of query part into credentials part of URL
• As a consequence move cluster name out of credentials part into path part
• Allow both neo:// and neos:// schemes to be used. neo:// means always without SSL and neos:// means always with SSL. Even if neos:// URL comes without credentials embedded into it - they can be obtained from elsewhere.

I need this change in wendelin.core 2 which needs to take a zurl and compute a mountpoint path that corresponds to it, so that multiple several zopes that use the same NEO storage, could be associated with the same single WCFS instance.