fix binaryFun

1. Make binaryFun correct for integer comparison.
2. Remove import of half of phobos for 98% cases in phobos.

`sort`, `cmp`, `find`, `startsWith`,  `sum` and other algorithms would be compiled faster.

See also: #2701, [Issue 13253 - use more scoped imports in phobos](https://issues.dlang.org/show_bug.cgi?id=13253)

`reduce!"a + b"` is a common code. Also lambdas is not good stuff in library because compiler can not compare them.
With lambda 
```D
auto s1 = reduce!"a + b"(ar);
auto s1 = reduce!((a, b) => a + b)(ar);
auto s2 = sum(ar);
```
will produce *three* reduce function. But with `sum = reduce!"a + b"` only *two*.