DOC: added compatibiliy warning in whatsnew and io for HDFStore

Author: jreback

doc/source/io.rst

@@ -1158,6 +1158,13 @@ Notes & Caveats
         store.append('wp_big_strings', wp)
         store.select('wp_big_strings')
 
+Compatibility
+~~~~~~~~~~~~~
+
+0.10 of ``HDFStore`` is backwards compatible for reading tables created in a prior version of pandas,
+however, query terms using the prior (undocumented) methodology are unsupported. You must read in the entire
+file and write it out using the new format to take advantage of the updates.
+
 
 Performance
 ~~~~~~~~~~~

doc/source/v0.10.0.txt

@@ -216,7 +216,6 @@ Updated PyTables Support
 
 :ref:`Docs <io-hdf5>` for PyTables ``Table`` format & several enhancements to the api. Here is a taste of what to expect.
 
-
 .. ipython:: python
    :suppress:
    :okexcept:
@@ -319,6 +318,12 @@ Updated PyTables Support
    import os
    os.remove('store.h5')
 
+**Compatibility**
+
+0.10 of ``HDFStore`` is backwards compatible for reading tables created in a prior version of pandas,
+however, query terms using the prior (undocumented) methodology are unsupported. You must read in the entire
+file and write it out using the new format to take advantage of the updates.
+
 N Dimensional Panels (Experimental)
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~