04d5337b75
closes #2008 Changes: - Drop `asObservable()` since it is deprecated in RxJS 5 (see the [migration guide](https://github.com/ReactiveX/RxJS/blob/master/MIGRATION.md#operat ors-renamed-or-removed)). - Drop `+` from hero search query URL: `app/heroes/?name=${term}+`. At best it is interpreted as a regex op that serves no purpose, at worst, it gets interpreted as a space (cf. [HTML 4.01 section 17.13.4](https://www.w3.org/TR/REC-html40/interact/forms.html#h-17.13.4) ). - Rename `searchSubject` to `searchTerms` - Other minor tweaks to prose. This work is in preparation for #1924. Note: toh-6 tests pass.