Much better animation for ios

Fixed duration
Merge pull request #1504 from driftyco/wip-ios7-animation-1

feat(nav): Better iOS 7 navigation and nav bar animations
chore(): move demos out of source files
chore(build): make demos use correct folder
ngValue uses a value instead of variable
fix(ionRadio): correctly interpolate ngValue instead of compiling

Closes #1464
syncing with original fork