Bitwise operation weirdness
It seems like `pd.Series([x]) | pd.Series([y])` with `x, y` integers returns `pd.Series([x | y]).astype(bool)`. This is a reasonable semantic, but `pd.Series([x]) & pd.Series([y])` seems to return `pd.Series([x & y % 2]) == 1`, which is a lot weirder. Is there a justification for this? I couldn't find one in the documentation (`&` is hard to search!), so it may be a bug.
