CRM-14798 - crmUi - Add "goto()" helper function

Example: <button ng-click="goto('home')">Go home!</button>

This allows us to use buttons instead of <A HREF>'s -- which makes it easier
to maintain consistent styling in a button bar.
CRM-14798 - civicrm.css - Styling for disabled buttons
CRM-14798 - crmCaseType/edit.html - Only allow saving of valid forms
CRM-14798 - crmCaseType/timelineTable.html - Fix validation of hidden fields
CRM-14798 - crmCaseType - Fix handling of labels+validation

In our UX, labels are supposed to turn red when a field becomes invalid, and
they're supposed to include a red "*" if required.  This adds an Angular
directive to enforce both.
CRM-14798 - civicrm.css - Apply ng-invalid styling for <input>s but not <form>s
CRM-14798 - caseTypeDetails.html - Display warning when changing caseType.name
Merge pull request #3590 from totten/master-crmCaseType-validate

CRM-14798 - crmCaseType - Validation fixes