Signin Validation

closes #3120
- create `validateAndAuthenticate` action to validate, send `authenticate` action on success, notifications on error
- signin template uses `validateAndAuthenticate` action instead of `authenticate` action
Merge pull request #3159 from darvelo/signin-validation

Signin Validation
New edit user UI
Prevent stacking notifications during rapid toggle

No issue
-Call notifications.closePassive after the resolution of the
 promise that generates the notifications. Otherwise multiple
 promises can stack up after notifications have been cleared,
 which results in a bunch of stacked notifications.
-Remove some unnecessary propagation of rejected promises from
 action handlers that can result in unhandled reject errors.
Fix up route parameter validation

Closes #3169
-Replace javascript methods that are not available on all
 supported browsers with lodash methods.
-Add returns to transitionTo calls in cases where the model
 hook should stop executing immediately.
Invite user API

closes #3080
- added users.invite() to add user from email with random password
- added `GET /ghost/api/v0.1/users/` to invite users and resend
invitations
- removed one user limit
- added global utils for uid generation
- changed some „“ to ‚‘
Fix direct access to settings/user

closes #3162
- removes injection of user object in application route's beforeModel
- removes injection/cleanup of user object in signedIn/signedOut actions
- removes loading of user and passing to signedIn action in signup/setup controllers
- adds 'user' property to session object
- updates header nav to reference session.user
- sets model of settings/user route to session.user and forces reload
- on leaving settings/user, rollback any unsaved changes
Merge pull request #3176 from PaulAdamDavis/2422-edit-user-ui

New edit user UI
Merge pull request #3181 from jaswilli/ember-misc

Prevent stacking notifications during rapid toggle
Merge pull request #3184 from jaswilli/issue-3169

Fix up route parameter validation
Merge pull request #3185 from sebgie/issue#3080

Invite user API
PostSettingsMenu: Don't save new posts, reset values on failure

Closes #3158, Closes #3143, Closes #3134
- Added `model.rollback()` when PSM fails to save.
- Added `showErrors` and `showSuccess` helper functions to PSM to abstract
  closing and showing of notifications.
- Added `togglePage` action to indirect the setting of `page`.
- Removed `isStaticPage` property in favor of `togglePage` action
- moved `updateSlug` error catching to outer promise (slugGenerator promise)
- modifying the `page` and `published_at` properties will no longer cause a new post to save
- Close passive notifications on published date parse fail
- Removed promise creation in catch statements

- Changed tests to click on label, rather than the input for
  .post-setting-static-page.
Merge pull request #3180 from novaugust/psm-reset-on-error

PostSettingsMenu: Don't save new posts, reset values on failure
Merge pull request #3174 from kevinansfield/session-user

Fix direct access to settings/user using session.user CP