Fixing the bug for IE9

To fix the IE 9 bug, I put //= require jquery.placeholder in
application.js. This file is located in
app/assets/javascripts/application.js. Then, I added thislast line in
the file app/views/accounts/new.html.slim:  $('input,
textarea').placeholder();
Break topics hash loop if it is nil
Merge pull request #406 from sradutta/develop

Fixing the bug for IE9
Merge pull request #420 from jluria/jl-fix-lesson-planner-view

Break topics hash loop if it is nil
better fix for homepage url
properly fix jq.placeholder