cleanup: evas_macros.h - less comparison between signed and unsigned errors
cleanup: evas_macros.h - less comparison between signed and unsigned errors

update macro to do fine with unsigned integers (avoids width and
height getting below 0) and force casts.



git-svn-id: 24a995eca3b83137dd7eab3408044d7832e202f7@52425 7cbeb6ba-43b4-40fd-8cce-4c39aea84d33

antognolli/Evas,antognolli/Evas,antognolli/Evas,antognolli/Evas