Autocomplete

@danmaclean This PR adds back in autocomplete to a revised, tidied up, features form. Per the screengrab below, it now searches for an experiment and finds the genome from that. Have a play and let me know if that works appropriately.

![features-by-range](https://f.cloud.github.com/assets/14839/422086/d111be76-ad1a-11e2-8edf-d2d6ad2a3082.png)