Some pretty brute-force compiler warning fixes

warning:
  narrowing conversion of ‘rect.FIFE::RectType<int>::w’ from
  ‘const int’ to ‘Uint16 {aka short unsigned int}’ inside { } is
  ill-formed in C++11 [-Wnarrowing]

Closes #789
Merge pull request #824 from fifengine/t789

Some pretty brute-force compiler warning fixes