Display current project name in main window

Supersedes #6878.

This implements #2281, displaying the project name in the Brackets window title.
I felt bad about these whitespaces things when this was finally merged. This was my first PR, and the whitespace was removed automatically. I kept considering adding it back, but it was mentioned or asked for. If someone had asked for it to be restored, I would have gladly done so. I've been trying to watch whitespace removal since this.

It's fine, I know how it is to be frustrated by changes like this. ;)