feat(directive): translate attributes using directive

Add to the translate directive the ability to act on attributes. Using
the translate-attr-ATTR as an attribute, ATTR will be translated.
translate-default, translate-value and interpolation are possible.

Closes #568
feat(directive): translate attributes (optimize process flow)
Merge branch 'feature/translate-attributes' into canary
feat(storage): rename set() into put()

The new api (put, get) is capable with AJS' $cacheFactory.

BREAKING CHANGE: This marks storage.set() as deprecated. In the
next major release v3, the old method `set()` will be dropped in favor
of `put()`.

Relates #772