v0.2.2: add support for translating directly into the element

By specifying the "content" attribute in a translate-child attribute
list the translated text will be added directly to the element using
`element.html()`. This is useful in cases where you need the translation
to occur before another directive which has a higher priority than the
default translate directive.

v0.2.1

remove logging statements

v0.2.0: rewrite `translate-child` and replace attirbutes with translate format

`translate-child-into` and `translate-child-key-into` have been removed.
To translate into an attribute you now specify it before the translation
key in the `translate-child` attribute as so:
````
<a translate-child="(aria-label,title,!translate)=SOME_TRANSLATION.KEY"></a>
````

The attributes should be comma delimited and prefixed with a `!` when you
want the translation key to be set instead of the translated value.

v0.1.7: add suport for multiple attribute targets in `translate-child`

This adds the ability to specify multiple attributes to set the
content for.

It also removes the mutual exclusivity of `translate-child-into`
and `translate-child-key-into`.

v0.1.6

Add ability to exclude parent base translation keys with the translate-exclude-parent-base attribute.

v0.1.5

support using dtrwTranslate without config

v0.1.4

remove babel polyfill dependency

v0.1.3: add dtrwTranslate service

Creates a dtrwTranslate service with a method that prefaces a
provided translation key with the configured base key and
the expected state prefix.

initial release

v0.1.1

bump version number