hdf5

[svn-r2691] 
Purpose:
    1. fix multiple defination warnings at sgi platform
    2. adding chunking information from hdf4 to hdf5 property list.
Description:
    1. Orginally global varibles were defined at one header file and this
       header file were included by other .c file and .h file so multiple warnings are
       generated.
    2. Chunking information was not included in the previous version.
Solution:
    1. use "extern" to define global variables at h4toh5util.h file and define global variables
       at h4toh5main.c
    2. retrieve the chunking info from sdgetchunkinfo and GRgetchunkinfo and store these information
	into hdf5 property list.
Platforms tested:
      eirene,arabica,paz,gondolin