Some test cases incorrectly rely on the side effect of other test cases
importing `NgMatchers`. This commit fixes this by making `expect` in
`core/testing_internal` properly typed.
Mostly, removing things that were never intended to be exported publicy.
BREAKING CHANGE:
The following are no longer publicly exported APIs. They were intended as internal
utilities and you should use your own util:
```
browserDetection,
dispatchEvent,
el,
normalizeCSS,
stringifyElement,
expect (and custom matchers for Jasmine)
```
Jason Choi
Victor Berchet
Tobias Bosch
Julie Ralph
ScottSWu
Alex Eagle
ScottSWu
Misko Hevery
Igor Minar