Code review comment for lp:~optimisme/pantheon-files/fix-995762

Hi Victor:

- I don't know how to use "extern void" if you have an example of it I will be pleased to learn from it and change my source.
- I fixed the "vala" line jump styles, I copied my source from the other plugins and I assumed their source was properly styled.
- I do not see important style differences with my source and the rest of the c files, in fact I copied/pasted most of the source from the "trash" functions.
- I removed the non used source from "pantheon-files-ui.xml"