[Waves theme] Trimming unnecessary nodes in the wallpapers

[Luya Tshimbalanga]

I took an opportunity to look at Waves background and noticed a
tremendous amount
of nodes for curves causing a huge slowdown to my x86_64 workstation.
Removing some of them have reduced the original size from 208 to 186 KB.
The blurred dark flame is made with less node though it could be tweaked
further instead of the bunch of planes. I have added some sparks from
the flames.

You can view the preliminary result on http://luya.fedorapeople.org/test/

There are more trimming to do to reduce the size of the file.

Luya