docs(guide/i18n): fix a typo

Closes #5651
docs(forms): show directive name instead of link path
chore(inputSpec): fixed typo
docs(form): changed capitalization in CSS classes section

In order to improve readability from "Is set" (confused on my screen as 'Ls set') updated the
capitalization describing the setting of 4 CSS classes.

Closes #5642
Merge branch 'master' of https://github.com/angular/angular.js