MetadataWrapper: chain up meta table

The MetaTables were being shielded by MetadataWrapper layers,
effectively losing the lower (e.g. source) MetaTable.

This is bad. So let's chain the table up instead, since MetadataWrappers
will NEVER have their own MetaTable.
ICSFormat: set physical pixel sizes

Since we have calibrated axes, and potentially have pixel sizes in the
ICS Metadata, why not use them to calibrate these axes properly.
AbstractReader: change comparison in setSource

In the final setSource(RandomAccessInputStream) method, we were checking
for stream object equality.

This seems too strict. Instead, let's check String.equals on the
fileNames.

This should prevent files from being opened multiple times
unnecessarily.
Bump to next development cycle

Signed-off-by: Mark Hiner <hinerm@gmail.com>