Change default blog URL for development.

* Move `production` section above `development`.
Removing prototypal i18n code

refs #16, #17, #18, #19, #20, #21, #3801

- This code was a prototype system built when Ghost was still a prototype.
  It was never fully implemented and hasn't actually worked for ages.
- Now that the admin is in Ember, it's likely we'll need a very different
  system.
Move Models module to have an init method that sets up all models

resolves #2170

- creates a models.init() function that requires all other model files
and caches them.  This is opposed to the previous functionality where
when you require('./models') it would immediately require all other models.
Now it's done when you want.

- Updates all tests to reflect the new structure of the model module
Reset slug input text box after invalid input.

No Issue
- When an invalid, all whitespace slug is entered into the
  slug input in the post settings menu, it's rejected but
  the input's value still remains the same.  This resets the
  input back to its original value.
- Added test for the above behavior.
- Only show success notification if slug was actually changed.
- Convert whitespace from tabs to spaces in post-settings-menu.hbs
Center default user-error (404, etc.)

See #3810
- Only thing missing: <div id=“container”></div>. Added.
Merge pull request #3812 from felixrieseberg/iss3810-404

Center default user-error (404, etc.)
Merge pull request #3767 from jaswilli/clear-ws-slug
Merge pull request #3734 from rwjblue/change-default-development-url

Change default blog URL for development.
Working CopyHTML shortcut

closes #3481
- Pressing Ctrl/CMD+Shift+C in the editor will open up a modal that
contains the generated HTML for either the selected text or the whole
post
Merge pull request #3784 from felixrieseberg/iss3481
Merge pull request #3777 from hswolff/lazy-models

Move Models module to have an init method that sets up all models
Merge pull request #3802 from ErisDS/i18n

Removing prototypal i18n code
Removing remaining references to Polyglot

refs #3802
Change Ember function.property() to Ember.computed

Closes #3417
Merge pull request #3452 from novaugust/property-to-computed

Change .property() to Ember.computed