Update main_controller.rb

Made the changes from earlier comments... mostly just adding '%' to many of the searches
Update main_controller.rb

Made edits to what results end up in the @topics array... THis should add more results, and not exclude incorrectly... and I made the default to search the desc and the link text too.

I hope I have done the array manipulation right with:
@topics = @topics + (@topics2 - @topics)
Merge pull request #303 from Connoropolous/Robs-1st-edits

Robs 1st edits