Removes objectTypeModelMap to reduce circular dependency.

refs #2455

- also note areas where we still have lazy loading of modules.
- moves one lazy loading to non-lazy require.
Update Patterns Sass Formatting

Continues on from #4342

- Reformats the Sass to match our new style (property order, comments, & white space)
Add footnotes extension to showdown

refs 1318
- based on Markdown Extra https://michelf.ca/projects/php-markdown/extra/
- allows [^n] for automatic numbering based on sequence
Improvements to the permalinks UI

Closes #4454

* Relies on Flexbox more heavily
* Adds JS to simulate how it should work
Reverting mysql to 2.1.1

- Unfortunately mysql has changed the way it handles the charset setting such that
it now causes encoding issues on many setups where 'utf8' is apparently not the
correct setting.
- We need to revert this upgrade until the issue is fixed or we have a way to handle
it nicely for our users.
Merge pull request #4475 from ErisDS/revert-mysql

Reverting mysql to 2.1.1
Version bump to 0.5.5
Update Tags Management Markup

References #4248

- Updates the markup & classes for the tag management settings menu, as they've fallen behind now we've renamed the 'right-outlet' to 'settings-menu'
Merge pull request #4480 from PaulAdamDavis/update-tags-markup

Update Tags Management Markup
Posts view: some DRY.
Merge pull request #4469 from PaulAdamDavis/permalink-improvs

Improvements to the permalinks UI
Loads correct screen after author refreshes page in editor

closes #4415
- corrected logic around author check
- fixes a bug where it was possible to see editor for other author posts
Make tokens URL safe

Base64 encoding causes some issues when the token is URL encoded
as the = symbol is not a valid URL character. We replace any =
symbols with a - as this is valid in a URL, but is guaranteed
not to appear in a base64 string. This fix ensures that Ghost
password resets work with mail providers such as Mailgun that
add their own tracking redirects

closes #3872 (for real this time)
Fix updateConfigTheme method.

No Issue
- Fix exception being thrown when updateConfigTheme called before
  settingsCache fully populated.
- Remove unnecessary check in a conditional in the migration command
  builder.
Merge pull request #4401 from PaulAdamDavis/sass-cleanup

Update Patterns Sass Formatting
Merge pull request #4493 from jaswilli/settings-migration

Fix updateConfigTheme method.
Merge pull request #4488 from Gargol/issue-4415

Loads correct screen after author refreshes page in editor
Merge pull request #4490 from thisishugo/url-safe-tokens

Make tokens URL safe
Fix up single post routes.

No Issue
- Add local store lookup back to edit route.
- Prevent entry into route when an author is not the owner of a post
  even if model is passed in.
- Clean up references to pagination as there's no pagination going on.
Tags management api hookup

Ref #4248
- Added tags settings menu
- Added basic new, edit, delete, and save actions
- Show actionable edit buttons dynamically based on tag state
- Infinite scroll
- Closing the tag settings menu rollbacks your changes
- Removed not-yet-implementable code