Simplify publish date checks

Fixes #814

- Changed to compare instances of `moment` using it's built in
comparison function instead of string compare with the date from the
database.
- Ensure compared date is parsed with the correct formats that we were
supporting before #1107.
- Moved date formats to variables to reduce chance for error in future.
add a `target` arg to `grunt test-functional`

The idea here is to slightly speed up test development by allowing you
to specify a single test file to run.
Keep the status code generate by connect in case of error.

The status code generate by connect/express in case of error was always
replace by 500 status.
Update package.json

Update grunt-contrib-watch
Allow themes to provide custom error template.

fixes #1212, #1213
Store the Bookshelf instance on the Bookshelf module

- Assigns the ghostBookshelf instance to the Bookshelf.ghost property
Fixing client-side jslint exclude

- Gruntfile had an exclude for all of client/assets rather than client/assets/vendor
- Fixes missed jsLint errors
Show proper error message when image upload fails

fixes #994
Add tooltip text to icons in admin section

Closes #1178

* Add tooltip text to assorted icons within CMS
* Add tooltip for blog URL to Ghost logo
* Change 'Options' to 'Post Settings'

Change 'Options' to 'Post Settings'
Merge pull request #1185 from commadelimited/1178-add-title-attribute-to-action-items
Merge pull request #1197 from halfdan/994-image-uploads

Show proper error message when image upload fails
Merge pull request #1211 from matheusazzi/patch-1

Update package.json
Merge pull request #1167 from manzoid/add-target-to-grunt-test-functional

add a `target` arg to `grunt test-functional`
Merge pull request #1204 from Gotvitch/error-code

Keep the status code generate by connect in case of error.
adds prefix option to tag helper

        closes #607

 - added prefix attributetor tags helper
 - will add prefix only if tags are present
 - adds unit tests for prefix
Added server validation for location field
Merge pull request #1145 from b1nd/merge
Validate negative numbers in the posts per page setting

issue #1236
- added validation to not allow number less than 0
Merge pull request #1236 from Tmeister/validate-negative-post-per-page
Removed special character from SCSS

Replaced it with the escaped unicode version (\21AA).