update copy and css styles
Bug 835506: Delay download for analytics
Add styling for invalid form fields

Our sandstone field styling adds a box-shadow and overrides Gecko's native styling for invalid fields. This rule applies our own style so errors still look nice in Firefox. This uses a proprietary selector so it only works in Gecko.
Merge pull request #846 from Nobox/download-tab-analytics

Bug 835506: Delay download for analytics
Merge pull request #842 from alexgibson/student-ambassadors-bug-859564

Update copy and styles on Student Ambassadors form bug 859564
Merge pull request #847 from craigcook/form-error-style

Add styling for invalid form fields
Bug 867658 Adding T-Shirt promo banner to homepage