hdf5_ep

[svn-r8999] Purpose:
New feature.

Description:
Add two new windows projects and one testing batch file.
Update two testing batch files.

Solution:
1. Add a new project h5diffdll, which will generate h5diff dll tool.
2. Add a new windows project h5repackdll, which will generate h5repack dll tool.
3. Add a new hdf5 tool testing batch file -- testhdf5tools.bat, which
   calls h5dump, h5diff, h5ls, h5import, and h5repack tools.  Now all the available
   hdf5 tools can be tested with one batch file.
4. Updated difftest.bat and repacktest.bat testing batch files.

Platforms tested:
Visual C++ 6.0 on Windows XP and 2000.
(will test with .NET on XP after this check-in.)

Misc. update: