Add the new body classes

closes #1967

- adds paged to eventually replace archive-template
- adds page-template to eventually replace page
- changes custom page template class to be page-slug instead of
  page-template-slug
Makes the Ghost application more express middleware friendly.

refs #827

- Moves ./index to use Ghost in a similar manner to how someone uses
Ghost as an npm module.
- Allows Ghost to be cleanly mounted on another express application
on any arbitrary endpoint, all you need to customize is the mount path.
Add alternative names for pg

refs #3864
- map alternative valid pg names to pg
Resets the scroll position on controller content change

When scrolling through the preview of a long article, if the
post was changed the scroll position of the preview would
remain the same.
Fix user cover images

No issue

The cover image method in the settings/user controller returned the correct asset URL, but not the corresponding CSS which is needed to show it correctly.
Merge pull request #3914 from halfdan/3864-db-config

Add alternative names for pg
Merge pull request #3819 from studioromeo/reset-preview-scroll-position

Reset preview scroll position when post item is clicked
Merge pull request #3934 from PaulAdamDavis/fix-cover-image

Fix user cover images
Remove permissions from configuration API

closes #3909
- Remove permissions from configuration API
- Remove permission setup from integration test
- Remove permissions from permissions.json
Update About page styles

Closes #3919

With the move to new global styles, the about page styles got a bit borked. This fixes those.
Merge pull request #3912 from halfdan/3909-config-api

Remove permissions from configuration API
Implement About Ghost page

Closes #3568
- Deleted html placeholders in client
- Added new grunt task, buildAboutPage, which 1)creates -contributors.hbs partial and 2) downloads contributor avatars
- buildAboutPage is called by anything that does an emberTemplates task
- Removed unused code from ghostpaths
Merge pull request #3907 from PaulAdamDavis/fix-about-styles

Update About page styles
Merge pull request #3575 from novaugust/about-ghost

About ghost page
Static integration of the new PSM

Reference #3932

Take this, and make it work.
Enlarge mobile matchMedia max-width

Closes #3941

It now matches the mobile MQ in CSS - https://github.com/TryGhost/Ghost/blob/master/core/client/assets/sass/components/navigation.scss#L163
Bumping version to 0.5.2-1

no ref
- because Hannah said "someone"
Merge pull request #3935 from PaulAdamDavis/new-psm

[WIP] New post settings menu
Merge pull request #3943 from halfdan/patch-2

Bumping version to 0.5.2-1
`grunt dev` calls default task

Closes #3942