Updates to Win32 thread-local storage cleanup when the thread-safe library is built on Windows. Previously, thread-local storage was not cleaned up, causing resource leaks.

Fixes HDFFV-8518, HDFFV-8699

As a part of these changes, the thread-safe + static library options are declared unsupported since the solution relies on DllMain. A solution for the static library is probably doable, but requires much more complicated surgery and has been deferred to HDF5 1.8.14.

Tested on:
    64-bit Windows 7 using VS 2012 (changes only affect Windows)

git-svn-id: https://svn.hdfgroup.uiuc.edu/hdf5/trunk@24961 dab4d1a6-ed17-0410-a064-d1ae371a2980