Alternate compiler for translation strings
Travis doesn't have Node 0.10.26
Support turning off {{t}} helper's default <span>

If `Ember.FEATURES.I18N_TRANSLATE_HELPER_SPAN` is set to
`false`, the `{{t}}` helper will not emit a `<span>` by default.

If `Ember.FEATURES.I18N_TRANSLATE_HELPER_SPAN` is set to
`true`, the `{{t}}` helper will use a `<span>`.

Otherwise, the `{{t}}` helper will use a `<span>` AND emit a
deprecation warning.

In all cases, the `{{t}}` helper now uses Metamorph tags.
If a `tagName` is specified, the helper gives that element
a unique ID based on `Ember.uuid`.

Resolves #33 and #111
README: correct Ember.ENV.I18N_COMPILE_WITHOUT_HANDLEBARS

The variable that is checked is
`Ember.ENV.I18N_COMPILE_WITHOUT_HANDLEBARS`, not
`Ember.I18n.I18N_COMPILE_WITHOUT_HANDLEBARS`.

cf https://github.com/jamesarosen/ember-i18n/pull/115
v2.1.0
Removed deprecation warning for those who've opt-in to I18N_COMPILE_WITHOUT_HANDLEBARS. Also fixed a typo in the warning message.
Remove check for Ember.I18n.fire

Ember.I18n no longer supports Ember 0.9.x, so Ember.Evented will
always defined `trigger`, not `fire`. Thus, we don't need to check
which one to call.
Don't warn on missing translations

If clients want a warning, they can listen for the `missing` event
on `Ember.I18n`.

References:
 * https://github.com/jamesarosen/ember-i18n/pull/117
 * https://github.com/jamesarosen/ember-i18n/issues/121
 * https://github.com/jamesarosen/ember-i18n/pull/122
compileWithHandlebars uses saved off warn helper
Makefile: slightly better messaging

Hide commands and print out friendly success messages.
script/run exits with status 1 on errors

The build has been failing on some of the prerelease versions
for a while, but Travis was still reporting success because the
test command always exited successfully.
Separate Travis Builds

Travis supports running a matrix of separate builds. This (a)
paralellizes the build process and (b) makes it easier to see when
the specs are failing on one particular environment (set of
dependencies).

This commit

 1. introduces a new "test" task that runs `script/run` against the
    current environment (with no prerequisites) and uses that in Travis
 2. eliminates Travis builds on Node 0.11. That build was mostly
    redundant since this project isn't terribly sensitive to changes
    in Node.js.
 3. moves all dependency installation on Travis into its install step
 4. adds a long series of test configurations to the `travis.yml`
    `env` matrix

References:

 * http://docs.travis-ci.com/user/build-configuration/
 * http://docs.travis-ci.com/user/caching/
 * http://docs.travis-ci.com/user/languages/javascript-with-nodejs/
add sinon.js to test environment
Use sinon spies in specs
{{t}} helper warns if key parameter is unquoted

The helper currently treats `{{t "some.key"}}` and
`{{t some.key}}` the same -- both use the "some.key" translation.
In the future, we would like to support bound keys like
`{{t user.type}}` or even `{{t "message" "welcome" user.type}}`.

Thus, we emit a warning during a transitionary period.

References:

 * https://github.com/jamesarosen/ember-i18n/issues/41
 * https://github.com/jamesarosen/ember-i18n/issues/66
 * https://github.com/jamesarosen/ember-i18n/pull/113
v2.2.0
warn helper doesn't take a second argument

We were calling `warn(message, boolean)` in several places.
That's the signature of `Ember.warn`, but not of the local
`warn` helper. That meant that warnings were *always* emitted.
v2.2.1
Fix TranslateableAttributes tests on Ember Canary

These tests included
```js
this.renderTemplate('{{view titleTranslation="foo.bar"}}');
```
which breaks on Ember Canary because the `{{view}}` helper no
longer assumes `Ember.View` by default, but instead asks the
container for `view:default`.

This commit changes `renderTemplate` to create an `Ember.Container`,
register an anonymous subclass of `Ember.View` as `view:toplevel`,
and set that container as the container for the created view.
Execute Ember.uuid if it's a function

In Ember 1.7.0-beta.5, `Ember.uuid` is actually a function.

Closes #133