remove owner_title from default selected columns, and add creation & modification dates in more columns

portal_caches tool is expected to allow only Cache Factory instances inside.
Fix tests to use Cache Factory instead of Cache Bag.

different kinds of Cache Plugins.
This API change allows developer to create complex cache structures which
can contain arbitrary set of Cache Plugins and / or Cache Bags (Cache Factory).
Extend Cache Factory so it can return RAM based Cache Plugin instance by its Uid.
Fix tests to reflect changes.

contain Cache Plugins.
Unify in one function cache factory uid generation.

Really use memcached backend for testIngestionWithFlare (it was not setup properly).

Add back wrongly removed volatile conversion caching.
Use new set / get Cache bag API.

Fix tests (DMS) to use by default Cache Bags.
Fix some dead code and clean up.
Move cache initialization away from DMS into Cache Factory.

this commit fixes a regression in ecb09a0d.

- various cleanup and split of code to make it more testable
- start writing some tests

Don' request netscape.security.PrivilegeManager.enablePrivilege("UniversalFileRead") if netscape.security.PrivilegeManager is undefined.
File upload tests will fail, and it seems the only way is to swith to WebDriver.