Utilize already existing method 'find_by_username_or_email'

check presence of email using include, dont use =~
FIX: make it possible to close popup-input-tips on touch devices, and position them a bit better
Refactor SpamRulesEnforcer so that each spam rule is in its own class
FIX: Various bugs with Category breadcrumbs
FIX: Mobile breadcrumb formatting
Merge pull request #1573 from railsaholic/use_existing_find_by_username_or_email

Utilize already existing method 'find_by_username_or_email'
Show Log In button at the bottom of the page body when login_required and not logged in