{{gh-path}} Handlebars helper, returning paths

- Uses utils/ghost-paths to resolve paths
- {{gh-path}} or {{gh-path ‘blog’}} for Ghost’s root (mysubdir/)
- {{gh-path ‘admin’}} for Ghost’s admin root (/mysubdir/ghost)
- {{gh-path ‘api’}} for Ghost’s admin root (/mysubdir/ghost/api/v0.1)
Implements setting specific body classes

closes #4116
- Adds css classes to settings views
Fix publish bar tag scrolling div

Continues on from #4128

- Increases height of tags div and adds `overflow-y: hidden;` to its parent
Fix button class on upload modal

no issue

- this makes sure that the cancel button on the upload modal gets the
  correct class
Merge pull request #3824 from felixrieseberg/iss3718-2

{{gh-path}} Handlebars helper, returning paths
Merge pull request #4143 from ErisDS/modal-button

Fix button class on upload modal
Merge pull request #4142 from PaulAdamDavis/fix-publish-bar-tags

Fix publish bar tag scrolling div
Enable cycling header levels with ctrl+h.

closes #3019

* Remove preexisting `ctrl+h` keymap.
* Add logic to cycle the header level.
  * Loops around after h3.
  * Sets cursor position to end of heading
  * Set initial level to h2.
* Remove `ctrl+alt+${NUM}` keymaps (as they do not work
  internationally).
Updating markdown help modal with new shortcuts

issue #3019
Undisable nProgress

Closes #4095

* Removes the line that killed nProgress for PSM
* adds to styles to make nProgress appear again (ht @halfdan)

IRC: http://107.20.237.151:8081/logs/%23ghost/20140922#pm51214
Merge pull request #4145 from ErisDS/pr/3484

Enable cycling header levels with ctrl+h.
Merge pull request #4120 from halfdan/4116-settings-classes

Implements setting specific body classes
Merge pull request #4096 from javorszky/enable-nprogress

Undisable nProgress
Version bump to 0.5.2-rc1
Rename helpers/ghostPaths.js -> helpers/ghost-paths.js

Refs #4144
Update top-gh-contribs to get contributors within last 90 days

Closes #4130
Merge pull request #4154 from tundal45/ghost_path_rename

[WIP] Rename helpers/ghostPaths.js -> helpers/ghost-paths.js
Merge pull request #4156 from novaugust/iss4130

Update top-gh-contribs to get contributors within last 90 days