Preparing lens flare branch
Add the lensflare shader
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare

Keep lens flare updated with master
minor modification to the blueish mood of lens flare
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare

Keep lens flare updated with trunk
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare

keep compatibility with master
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare
Merge branch 'master' of https://github.com/supertuxkart/stk-code into lensflare
merge with trunk + try to adapt to the new blur system
Try to tweak the lens flare without being too obvious
Add a description to the shader