Proposed changes to movie scraper dialog.

Changes
- Divided search between search by remote database id and search by movie title. Defaults to remote database id, if known.
- Replace "_" with " " in movie titles search string (in addition to ".").
- Updated german translation affected by changes.

Purpose
- Stop MediaElch from forcing me to enter the movie title manually after selecting the wrong movie.
- I use "_" instead of spaces in file names.

![bildschirmfoto vom 2014-03-29 11 22 49](https://cloud.githubusercontent.com/assets/7099464/2558031/881bb8da-b72c-11e3-98d7-d36e7e7c5590.png)