hdf5_ep

[svn-r18507] Purpose:

    Fix Bug 1730 (in 1.8)

Description:

    This is a fix for Bug 1730. Note that this fix is only going into 1.8,
    as there is a more desired fix prepared for the trunk, but we don't 
    want that one in 1.8 for compatibility reasons.

    This change adds a mechanism to the H5I interface to save returned
    ID structures for immediate re-use if needed. This addresses a potential
    performance issue by delaying the case when the next ID to be 
    registered has grown so large that it wraps around and needs to be 
    checked to see if it is available for distribution again.

Tested:

    h5committest, and manually on jam, amani, liberty, others.