Add empty create-embedded-comments-site test, for password login

It's named CreateEmbeddedCommentsSiteNewPasswordAccountSpec.
Add warning about unencrypted password.
Add E2E test: CreateEmbeddedCommentsSiteNewPasswordAccountSpec.
Add E2E test: CreateEmbeddedCommentsSiteOldPasswordAccountSpec.
Add E2E tests that test various combinations of jQuery and Modernizr

On the static embedding page, which embeds embedded comments.