Aurora gtk engine performance patch

let me start with benchmarking results (gtkperf):

1. all tests, 100 runs:
aurora-unpatched: 15.58
xfce-saltlake: 10.73
aurora-patched: 13.01

2. GtkComboBox test, 1000 runs:
aurora-unpatched: 19.52
xfce-saltlake: 6.11
aurora-patched: 8.81

as you see, here we have more than 2x speed improvement in widget rendering (which is actually much more than that, because benchmarking always lie)

the only drawback is that we loose rounded corners.

now, to the fun part: How To Get It On Your Machine!

1. uninstall aurora if you have it installed
2. download aurora source code, and unpack it
3. do the usual configure steps:
./configure --prefix=/usr --enable-animation
4. edit file src/aurora_draw.c
5. find function called "clearlooks_rounded_rectangle"
6. insert this text just after opened curly brace:
    cairo_rectangle (cr, x, y, w, h);
    return;

7. save the file, and execute "make && sudo make install"
8. profit!

screenshot with patched version (click for sullsize):