Inconsistent types in sequence() and range()

These functions are templated on a single type.  However, type inference is not smart enough to correctly infer the type of the following declaration:
```
size_t N = 10;
for (auto i: sequence(1,N))
  ...
```
The first argument is an `int` and the second is a `size_t.

We should be able to correctly deduce the expected behavior from the given types.