Icon wrapper around signing inputs

No issue

References https://github.com/TryGhost/Ghost-UI/commit/379a630e1bc1

- Adds `<span class="input-icon icon-mail">` around signing inputs to help match markup used elsewhere
Update Ember to latest stable (1.7.0).
Rework editor save button.

Refs #3834
- Change bindings and fix a forward reference.  Preparation for
  upgrade to Ember 1.7.0.
Ignore tables with pg_ prefix in pg getTables.

Closes #3825
- Fixes an issue where a PostgreSQL extension may create
  a public table and it gets caught up in the migration process.
Merge pull request #3837 from jaswilli/issue-3825

Ignore tables with pg_ prefix in pg getTables.
Merge pull request #3820 from PaulAdamDavis/input-icons

Icon wrapper around signing inputs
Pre & Next Links for Ghost_Head

closes #685
- Now that we have a ‘pagination’ meta object, we can implement
SEO-friendly `next` and `prev` ref links in `<head>`.
- This implementation works uniformly for anything that supports
pagination in the current schema (posts, tags, authors)
- Regex should make the implementation future-proof for additional
pagination
Merge pull request #3817 from felixrieseberg/iss685

Prev & Next Links for Ghost_Head
Change tests to accommodate pg differences.

Refs #2499
- Since PostgreSQL handles transactions differently than
  MySQL and SQLite3 there are differences in the way and
  number of errors that are returned.  Update tests to
  only check that at least one error of the proper type
  was returned.
Fix markdown/preview tab for mobile

Fixes #3813

- Add togglePreview action to controller
- Implement action and bind attributes
- Remove the now pointless
- Update to comply with issue suggestions
Merge pull request #3834 from rwjblue/update-ember-to-latest

Update Ember to latest stable (1.7.0).
Merge pull request #3836 from jaswilli/ember17-prep

Rework editor save button.
Merge pull request #3830 from wjake/issue-3813

Fix editor markdown tab
Merge pull request #3840 from jaswilli/pg-import-test

Change tests to accommodate pg differences.
Extract starting functionality into an exported class

closes #3789
- Create a GhostServer class to manage state
- index.js now calls start on the exported server
- Alter tests to expect a GhostServer instance
Removing hard-coded port number

closes #1391
Merge pull request #3851 from ErisDS/issue-1391

Removing hard-coded port number
Merge pull request #3815 from JoshWillik/extract-init

Extract the starting functionality into an exported class.
Replace the when promise library with bluebird.

Closes #968
Merge pull request #3826 from jaswilli/bluebird

Replace when with bluebird