Changes for Release 0.93

Enhancements:

1. The HeaderCard class has been modified to handle
The HIERARCH keyword convention.  The FitsFactory
now has methods set/getUseHierarch to enable/disable
this processing.

2. A new interface FitsElement has been added which
is implemented by the BasicHDU, Header, Data and FitsHeap
classes. It enables users to more easily deal with FITS data
at the byte level.  There is also a public method
getDataSize in Header to get the size in bytes
of the associated data element including padding.
The FitsHeap class has been made public.

Bug fixes:

1. Several bugs relating to null images were corrected.
(Thanks to Jens Knudstrup) (ImageData)

2. The handling of EOF conditions in array reads in 
the BufferedFile and  BufferedDataInputStream classes 
was made consistent with the behavior of java.io classes
reading byte arrays.

3. Several bug fixes implemented by Alan Brighton (and already
fixed in the Jsky distribution) were incorporated.

4. All references to the java.lang.reflect.Array.newInstance()
methods were modified to use new methods with the same signature
in ArrayFuncs.  These new methods throw an OutOfMemory exception
when an array cannot be created.  The JVM methods seem -- in
contradiction to the documentation -- to simply return null.
Previously the program could mysteriously crash when used to read large
files, when the null in a dynamic allocation was eventually
dereferenced.