Changes to look out for with new code in core and core template paths.

3.1updates

#Deprecated in Rails 3.1
<% form_tag %> #note the different erb tags below
<% form_for %> #this is only in regards to the form tag helpers
request.request_uri


#New syntax for 3.1 upgrade
<%= form_tag %> #3.1 requires the erb tags with the '=', or the evaluate and render tags for form helpers.
<%= form_for %>
request.url  #this is backwards compatible, request.request_uri will not work in 3.1