Revert "Split OMEROWrapper to CachingWrapper for directory use"

This reverts commit 6f69e3843e790b0481cae71e032d789984cf8cbe.

Conflicts:

	components/romio/src/ome/io/bioformats/CachingWrapper.java
	components/romio/src/ome/io/nio/PixelsService.java
Revert "General OMEROWrapper refactorization for passing directory"

This reverts commit d37c4c7806ccd81013eeaaf7940e05c4db2328f3.
Minimal refactoring; limits where Memoizers are created

There is almost certainly more cleanup that can be done in terms of
where the reader stack is constructed and how it is stored.  This is at
least a start, and is hopefully safe and minimally invasive.

See #10750.
Merge pull request #19 from melissalinkert/memoizer-refactoring

Memoizer refactoring