hdf5_ep

[svn-r15005] Purpose: Minor updates to Windows documentation.

Description:
-- INSTALL_Windows.txt:
   -- Update szip version number to 2.1
   -- Extra details for setting up 64-bit builds
   -- Explain adding HDF5 link settings more clearly
   -- Add link to FAQ
   -- Misc. typos and formatting
-- INSTALL_Windows_From_Command_Line.txt
   -- Add note about 64-bit support
-- INSTALL_Windows_Short_NET.TXT
   -- Add notes detailing features unsupported on VS.NET
-- INSTALL_Windows_Short_VS2005.TXT
   -- Add notes about extra features.