ENH: add new computation module and toplevel eval function
ENH: rewrite assignment operator as equal comparison for PyTables
ENH: add Expr based terms for pytables
ENH: add automatic query via frame.__getitem__
ENH: add boolean operators
ENH: add chained comparisons
BUG: provide automagic scope updating

This avoids need to pass local_dict/globals_dict explicity to
query/frame.__getitem__/eval
TST: added same_name_scoping tests to io/tests/test_pytables.py
ENH: add subscripting to eval expressions
ENH: added interpretation of 'in' in pytables Term syntax

which is syntactically equivalent of '='
TST: make sure py3.x behavior is expected
ENH: add local scoping with @lcl_variable syntax
ENH: add DataFrame.eval method and tests for local syntax
BUG: fix Term expression printing if the expression is not a string (e.g. an ndarray)

BUG: _ensure_term will now only coerce to a Term if its maybe_expression
     so will not coerce coordinate looking (e.g. list of integers or ndarray)
ENH: add in, not in, and string/list query support
CLN: add an R with/subset comparison script
DOC/TST: raise a ValueError on an invalid pytables query expression (rather than a NameError)
DOC/TST: jreback's: add doc compat and test for term compat