Install: Fix Theme settings are not setup in InstallController

Since InstallController purposefully does not extend AppController,
`$themeSettings` view variable is not populated.
Install: Minor style fixes for buttons and input classes

Need to use span11 for inputs (instead of default class configured in theme)
here.  This is because we are using input-append addons which screws up the
form size.
Merge branch '2.1-install'

* 2.1-install:
  Install: Minor style fixes for buttons and input classes
  Install: Fix Theme settings are not setup in InstallController
Fix: Missing $this in variable name

Closes #561
Fix: Don't set empty when multiple selection is allowed

Related: croogo/croogo@7433501
Update bake templates using the newer view style
Croogo::adminAction() accepts $confirmMessage argument

- When using 'POST', pass new confirmMessage to Form::postLink()
- Use the scriptBottom block
Merge branch '2.1-templates'

* 2.1-templates:
  Croogo::adminAction() accepts $confirmMessage argument
  Update bake templates using the newer view style