Scroll post-item-view into view

Closes #3998
- Scroll the active post into view on page load
- If the active post changes and the newly active post is offscreen, scroll it into the middle of the screen
Update downsize node module. Small test updates.

issue #4017
- downsize 0.0.5 -> 0.0.8
- downsize is now better at punctuation, update {{content}} and {{excerpt}} tests appropriately.

Conflicts:
	package.json
PSM: Reset 'Published Date'

Closes #4557
- The underlying issue is that the PSM is already loaded when Ember
routes from an existing post to a new post. Instead of resetting the
‘Published Date’ value manually (with jQuery), I’m using Ember’s
computed property setter to ‘refresh’ the cache for that property. I
believe that this Ember solution is better than manually going in and
resetting it with jQuery.
Update authentication initializer.

Refs #3492
- ember-simple-auth@0.7.2
Version bump to 0.5.6
About Page Tests

Closes #4508

Tests for:

- Version number is a number
- Database type is an allowed 1 of 3
- There are 20 contributors
- First contributor has an image tag and image src exists, alt tag, title tag, href to github
Move testem.json into client tests directory.
Merge pull request #4570 from jaswilli/update-simple-auth

Update authentication initializer.
Merge pull request #4587 from jaswilli/testem

Move testem.json into client tests directory.
Merge pull request #4579 from PaulAdamDavis/about-tests

About Page Tests
Update syntax in ember templates.

No Issue.
- Outlet names must be quoted.
- {{#each}} helper will no longer implicitly switch context.
  Change usage to {{#each foo in bar}}.
Merge pull request #4594 from jaswilli/ember19-prep

Update syntax in ember templates.
Change sitemap root location

Closes #4590

- Removes `-index` from the root sitemap
- Removes redirects (which send sitemap.xml to sitemap-index.xml)
- Adjust tests
Merge pull request #4599 from PaulAdamDavis/sitemap-index

Change sitemap root location
Fix reset token verification

closes #3872
closes #4603
- updated regex to work with url safe tokens
Merge pull request #4604 from sebgie/issue#3872-1

Fix reset token verification
Adds ctrl/cmd+s shortcut to whole application with a noop default

closes #4516
- shortcut for ctrl/cmd+s on application level
- shortens a syntax for any route that is using 'save' method, shortcuts object doesn't have to be defined at all, only the save action.
Merge pull request #4523 from Gargol/issue-4516

Adds ctrl/cmd+s shortcut to whole application with a noop default
Dry up tag saving behavior

Ref #4248
Merge pull request #4610 from novaugust/tag-save-refactor

Dry up tag saving behavior