round filter returns an float when precision=0

[davedash]

The expected (and documented) behavior is that you get an integer.

I looked at the tests and not only are the tests wrong, but they do a return rather than an assert.

This patch runs int() over the value returned if precision is zero.

[davedash]

Patch to deal with precision=0

[mitsuhiko]

The float is intentional for consistency with the Python round() builtin. Documentation was updated appropriately. If you need an integer, pipe through int.