CHECK_HEADERS([encore], [encore headers], [encore.h])
CHECK_LIB([giflib], [gif], [DGifOpen])
CHECK_HEADERS([giflib], [gif lib headers], [gif_lib.h])
CHECK_HEADERS([encore], [encore headers], [encore.h])
CHECK_LIB([giflib], [gif], [DGifOpen])
CHECK_HEADERS([giflib], [gif lib headers], [gif_lib.h])