Remove bootstrap column classes

These shouldn't have been in the PR and were missed.  Committing
this quick fix.
Merge pull request #365 from 18F/hotfix/html-for-logo-url

Remove bootstrap column classes for logo url field
Provide a different message for logged in users

When viewing the homepage after logging in, it asks you to
log in again.  Now that doesn't make much sense.  Instead,
let people go to their profile or applications.

This is a temporary change until the rest of the dashboard
app is built out, but provides a better experience than
we had before and is "good enough" for testing.

@dutchashell reviewed and is ok with this.
Merge pull request #370 from 18F/hotfix/logged-in-marketing-page

Provide a different message for logged in users
Whoops, the buttons actually need to link somewhere

Add the button links with link_to
Merge pull request #372 from 18F/hotfix/marketing-page-buttons

Whoops, the buttons actually need to link somewhere
fixing alt tags
css changes for mailer
Merge branch 'devel' of github.com:18F/myusa-server into feature/mail-branding