Fixes bug with completely sorted indexes where nrowsinbuf must be equal to or greater than the chunksize. refs issue #206 on https://github.com/PyTables/PyTables/issues/206
fix if chunksize is None
Merge pull request #238 from drakerlabs/develop

Fixes bug with completely sorted indexes where nrowsinbuf must be equal ...
Updated release note for gh-238

Alos a small refinement to the patch has been applied.