refactor(inputSpec): move call to `$digest` into `compileInput` helper
refactor(inputSpec): move call to `$digest` into `compileInput` helper

It is reasonable to expect a digest to occur between an input element
compiling and the first user interaction.  Rather than add digests to
each test this change moves it into the `compileInput` helper function.

ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js,ggershoni/angular.js