feat(whiteframe): add directive to apply md-whiteframe classes

[devversion]

@EladBezalel You got assigned for this issue, but everywhere is anyone assigned so I just did that PR. If you had a PR in progress, let me know :)

Fixes #6772

[devversion]

This needs to be improved?

[Frank3K]

What about the md-whiteframe-zN classes?

[devversion]

That's not said in #6772. But they still can be accessed through the dp number. Need more information from @ThomasBurleson if this is desired.

[Frank3K]

I understand DevVersion.

When checking older issues I have found that the -zN system had been deprecated in favor of the dpN system (issues #4706 and #4586).

Maybe it would be a good time to remove the -zN system now. The newly added directive can be introduced at the same time the old -zN class-based system is removed. But that's a decision that should be done by the team.

[EladBezalel]

to an element

[EladBezalel]

Besides the comments LGTM, @devversion thanks for helping me cleaning my queue :)

[devversion]

@EladBezalel Any time again :) - Applied the suggestions 😄

[ThomasBurleson]

• Attribute selectors are slow in IE.
• This limits the use of md-whiteframe to divs ONLY. Should be md-white-frame

[devversion]

I thought I should use a div here, as shown in #6772

[EladBezalel]

I don't know how i missed it, you DON'T want to restrict the use to use only div

[devversion]

Already updated. Just was confused from the description. Sorry.
PS: This is only the demo, it won't restrict the actual use of the md-whiteframe directive.

[devversion]

@ThomasBurleson - Added the missing -1 test, updated the breakpoints and annotated them and changed attribute selector to md-whiteframe (as already used here)