For performance, when an application does not plan to make use of stream
or image metadata, it should be able to signal this fact to the reader so
that it does not spend time on unnecessary parsing. For example, when the
Toolkit.getImage methods are eventually ported to use the Image I/O API,
there will be no reason for them to get involved with metadata.

  As of EA2, there is a capability for an ImageReadParam to provide such a
signal. However, this signal is not available to the ImageReader sufficiently
early for full advantage to be taken of it. Accordingly, the functionality
must be made a part of ImageReader instead of ImageReadParam.

  The functionality will be implemented by adding a new variant of the
setInput method, a boolean called 'ignoreMetadata', which if true will
release the reader from the requirement to supply metadata for as long
as the input source is not changed. For symmetry, another new variant
with only an Object parameter will be introduced.

  In sum, there will be three variants of setInput:

setInput(Object input, boolean seekForwardOnly, boolean ignoreMetadata)
setInput(Object input, boolean seekForwardOnly)
  -> equivalent to setInput(input, seekFormwardOnly, false)
setInput(Object input)
  -> equivalent to setInput(input, false, false)

The existing plug-ins override setInput(Object, boolean) and need to be
changed to override setInput(Object, boolean, boolean).

  The methods ImageReadParam.setIgnoreMetadata and getIgnoreMetadata
and the instance variable ignoreMetadata will be removed.