Merge pull request #7 from Tyilo/master

Try first Robot and then screencapture on OS X
make errors be thrown on non-Mac: move corner detection to ResourceReader (from RaffleImage), updated others to account for this; simplified OS testing
iterate over corners instead, speeding up failure if one couldn't be found
fix indentation and consistency on curly braces; various refactor fixes
If name couldn't be read, fix filename