Honor OPTIMIZE_PAGINATION_FOR_SPEED

[dkellner]

Eve 0.7 introduced a new setting called OPTIMIZE_PAGINATION_FOR_SPEED which will skip determining the total result count of a query to improve performance.

So far we always count the rows when we execute queries (see https://github.com/pyeve/eve-sqlalchemy/blob/master/eve_sqlalchemy/structures.py#L42), we could defer that to the actual calling of count, making sure we consider all the possible arguments this is called with (e.g. https://github.com/pyeve/eve/blob/3937c126f33fa5a426af985cf4d33550a4544108/eve/methods/get.py#L236).

[Zhanweelee]

Hope this feature could be supported.