hdf5_ep

[svn-r4548] Purpose:
    Code cleanup.
Description:
    Fix a few compiler warnings from the file creation property list -> generic
    property list conversion.  Also change a hard-wired value (8) for the
    number of B-tree key values to a value that uses the enum's generated by
    the compiler.
Platforms tested:
    FreeBSD 4.4 (hawkwind)