Don't add files selected in the Find window to "Open Recent" list

I've noticed that when I open a project, work on it for a day or more, close it and later want to reopen it again, it's usually already off the "Open Recent" list, because it's been pushed down by files belonging to this project. Specifically, the files I open in the sidebar don't get added there, but files opened from the Find window are. This is pretty annoying, because every time I want to reopen the project I need to look it up in the filesystem, so the Recent list doesn't really serve its purpose this way.

I've tracked it down in the source and I found the place where a document is passed from the Find window to the main window, and found a way to prevent it from being added to the Recent list. This could probably be done somewhere earlier on the path between creating the document instance and this point, but I didn't know how far down I can go without affecting other places. This version seems to work, though I'm still not 100% sure if it doesn't break anything.

I've also added `.DS_Store` to `.gitignore` because they got created for some reason and have come up on the list in GitX.

(Code shared under WTFPL.)