New method: LayoutHelper::themeSetting()

Similar to LayoutHelper::cssClass(), but operates on the whole "settings"
instead of just "settings.css"
theme.json: Default location changed to THEME/Config/theme.json

THEME/webroot/theme.json is still supported but deprecated

Closes #533
Add Block method + teach Blocks to use it
Teach filterBlockShortcode to use new RegionsHelper::block method
Add tests for block() method
Consistent code formatting across test methods
Merge branch 'pr/527' into 2.0

* pr/527:
  Consistent code formatting across test methods
  Add tests for block() method
  Teach filterBlockShortcode to use new RegionsHelper::block method
  Add Block method + teach Blocks to use it

Closes #527
Add migration for enable wysiwyg field
Use a class to identify area not to wysiwyg
Merge branch 'pr/530' into 2.0

* pr/530:
  Use a class to identify area not to wysiwyg
  Add migration for enable wysiwyg field

Closes #530
Change admin_add/admin_edit to use saveAll

Related to issue comment: https://github.com/croogo/croogo/issues/514#issuecomment-53711274

This change allows a user to extend the blocks plugin and save related data in another table.  Handy if you want your blocks to have site specific fields so they can become a lot more flexible.

I will release a plugin that demonstrates this soon.
Add better support to create input addons

- Options can accept either 'append' or 'prepend' setting
- Markup for addons are passed through the 'addon' setting
Don't apply formInput for checkbox wrappers when multiple => checkbox
Remove unnecessary class option
Use 'append' option when creating addons
Include 'hide' class in modal default element

Themes can override this by supplying its own modal element
Add page-heading and page-footer block similar to Common/admin_edit
Move helper settings to theme while still being overridable
Don't use default input class for radio and checkboxes
Use custom element for all setFlash() calls