APNGFormat: fix interleaved writing

Fixed the APNGFormat writer to use the source plane interleaved flag
instead of the output Metadata, as the flag is used to inerpret the
source pixels.
ImageIOFormat: fix interleaved use

Interleaved status should be pulled from source planes and not
destination metadata, as it is used for interpreting pixels.
Convert: remove unnecessary cropping creation

This was wrong for multiple reasons:

* It would crop from 0-0
* It was cropping on non-planar axes, when the crop was applied to
  planar axes.
* If no crop is specified the behavior defaults to axis lengths, which
  was the desired behvaior anyway.
AbstractReaderCommand: always log status

Removed safeguard for printing no more than once per second. This
resulted in very confusing messages - if an operation took less than a
second it might not print anything, or you would see one print statement
in a series of plane operations. Better to just remove it, as it is only
once per plane.
Convert command: limit plane processing by writer

Convert operates as a Reader command, so the number of planes processed
is controlled by the number of planes on the Reader. However, Convert is
a special case since it also has a Writer. There are cases where planes
will be truncated (e.g. writing to EPSFormat from a source with time
points). So on the Convert side of the processPlane workflow, nothing
should be done if beyond the Writer's plane limit.