Fix issue #1108
Merge pull request #1684 from Alayan-stk/patch-1

Fix issue #1108
Fixed #1680 (notification shown at wrong place after changing resolution).
Merge branch 'master' of github.com:supertuxkart/stk-code
Added some asserts to narrow down #1685.
Fixed #1687 (time too long when using many karts in ftl)>
Fixed compilation.