Update validator to 3.4.0

Closes #1379

- Convert to new api usage for both server-side and client-side
- Provide way require a negative response for boolean methods in
  default-settings.json
- Add field validation functional tests
  - Settings (General)
    - Title length validation
    - Description length validation
    - postsPerPage, numeric, min, max
  - Settings (User)
    - Bio Length validation
    - Location length validation
    - Url validation
  - Login
    - Email validation
  - Editor
    - Title required validation
Merge pull request #2286 from jondavidjohn/validator-upgrade

Update validator to 3.4.0
Change validation for posts 'page' attribute.

issue #2305
- changed validation for 'page' to expect '0' or '1', rather than 'true' or
  'false'
- Added a 'can change a post to static page' test
- Added a 'can change a static page to a post' test
Remove unused libraries.

refs #2326
- Remove unused libraries from core/client/assets/vendor/
- Add folder to .gitignore
- bower install is now handled by grunt init
Merge pull request #2335 from halfdan/bower-maeh

Remove unused libraries.
Merge pull request #2307 from Gudahtt/static-page-validation

Change validation for posts 'page' attribute
Fixing CodeMirror paths in GruntFile.js