add `getTitle` method to `meta.service`

I’m submitting a … (check one with “x”)

[ ] bug report => check the README and search github for a similar issue or PR before submitting
[ ] support request => check the README and search github for a similar issue or PR before submitting
[x] feature request

Current behavior There’s no interface which allows to retrieve the current page title using meta.service.

Expected/desired behavior metaService.getTitle method should be introduced, and should return the current page title:

• with callback
• without callback

Minimal reproduction of the problem with instructions

What is the motivation / use case for changing the behavior? The page title needs to be used on different parts of the corresponding page. There’re such scenarios where we need to supply this value to ngrx, etc.

Please tell us about your environment:

• Angular version: 2.0.X

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]

• Language: [all | TypeScript X.X | ES6/7 | ES5]

• Node (for AoT issues): node --version =

[stewones]

needing this too, would be awesome to have.

[logan-jobzmall]

Another use case: I have a title component that sits at the top of the mobile version of my site. I have the translation service that sets the title dynamically. Would be nice to able to display that value on this component. I guess I will need to find another way.

EDIT: I am now just using this.meta['title'].getTitle()