BUG: rolling_apply(..., center=True) should not append NaNs
DOC: Add notes explaining params is db driver dep. GH7573
Merge pull request #8266 from jnmclarty/SQL_params_note

DOC: Add notes explaining params is db driver dep. GH7573
ENH groupby: more user-friendly error message (GH7511)
Merge pull request #8281 from bthyreau/fix_grouper_errormessage

ENH groupby: more user-friendly error message (GH7511)
Avoid transaction context-managers for legacy SQL drivers (GH8277)

Eliminating contextmanager based transaction-handling

Rewriting as contextmanager

Code review fixes

Changing sqlalchemy version to 0.7.10 for python2.6
BUG: make sure that the multi-index is lex-sorted before passing to _lexsort_indexer (GH8017)
BUG: sparse repr of multi-index frame with a FloatIndex as a level was incorrect
Merge pull request #8278 from artemyk/remove_context_transactions

Eliminating contextmanager based transaction-handling
Merge pull request #8282 from jreback/sort

BUG: make sure that the multi-index is lex-sorted before passing to _lexsort_indexer (GH8017)
Merge pull request #8275 from seth-p/rolling_apply

BUG: rolling_apply(..., center=True) should not append NaNs
API: add ddof to expanding/rolling_cov()
API: add ddof to expanding/rolling_cov()