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)
```
Previously these symbols were exposed via platform-browser-dynamic, then we merged then into platform-browser
thinking that tools would know how to shake off the compiler and other dynamic bits not used with the offline
compilation flow. This turned out to be wrong as both webpack and rollup don't have good enough tree-shaking
capabilities to do this today. We think that in the future we'll be able to merge these two entry points into
one, but we need to give tooling some time before we can do it. In the meantime the reintroduction of the -dynamic
package point allows us to separate the compiler dependencies from the rest of the framework.
This change undoes the previous breaking change that removed the platform-browser-dynamic package.