Via Tender: Adding cast should trim whitespace on search

Assigned to Tender discussion #98. As reported in Tender:

Hi.

1. I've been experiencing problems when trying to edit genres in some movies. Take this as an example: http://www.themoviedb.org/movie/81930-pudor
   Whenever I try to add a new genre a get the message "Saving the overview failed. It's probably best to just try again" and nothing sets saved.

2. It would be nice that the search box triggered when you type an actor would use your text trimmered. It's usual to have spaces when you paste names. If you paste "Javier Bardem" the result is ok but if you paste "Javier Bardem " (notice the space at the end) the system suggests you to create a new actor.