vchoi_fork

[svn-r15015] Description:
    Detect chunks that are >4GB before dataset gets created and return error
to application.

    Tweak lots of internal variables that hold the chunk size/dimensions to
use an 'uint32_t', instead of a 'size_t', so that the integer size is constant.

    Correct a number of our tests which were creating datasets with chunks
that were >4GB and add some specific tests for >4GB chunk size detection.

    Minor whitespace & other code cleanups.

Tested on:
    Mac OS X/32 10.5.2 (amazon)
    Forthcoming testing on other platforms...