_eval_interval checks for zoo

This fixes the integral integrate(x*sin(3/x), (x, 0, 1)) as reported at
http://stackoverflow.com/q/27517233/161801.

The result of the added test was verified by integrating the derivative of
Si(1/x) from x = 0 to 1 in WolframAlpha.
Merge pull request #8629 from asmeurer/eval_interval_zoo

_eval_interval checks for zoo