update and minor spec fixes

I too was annoyed by Opera providing only a .deb, and extremely thankful for your RPM/SPEC effort (and everybody pointing to it).

While updating to the latest Opera Developer release, I made some fixes and enhancements. Most notably, you don't have to "--no-deps" anymore, because the package should now list the corrects Requires and Provides.

Please consider integrating my fixes by pulling them. I tried to make every relevant change a commit of its own.

To be done:
- better default fonts for Fedora
- better widget fonts (probably through GTK+ config?), looks really sucky on my machine
- better default icon in desktop file