docs(directives): Fixed typo from HMTL to HTML in line 283

HTML was mis-spelt as HMTL
refactor(booleanAttrs, ngSwitch): use link function instead of compile function where appropriate

Replace two compile functions that immediately return a post-link function with link function definitions instead.

Closes #5664
Merge branch 'master' of https://github.com/angular/angular.js