[Bleeding] Cleaned up unsafe casts. Addresses BUKKIT-844

Removed internal collection leaks from PluginDescriptionFile
BREAKING: PluginDescriptionFile.getAuthors() now returns List instead of
ArrayList

Various places with unsafe generics, notably List<Object> getList() in
Configurations are now referenced as <?>. This is nonbreaking, but
sourcecode will need to be revised when compiled.

By: Wesley Wolfe <weswolf@aol.com>

paper-api/src/main/java/org/bukkit/inventory/ItemStack.java

@@ -391,10 +391,9 @@ public class ItemStack implements Cloneable, ConfigurationSerializable {
             Object raw = args.get("enchantments");
 
             if (raw instanceof Map) {
-                @SuppressWarnings("unchecked")
-                Map<Object, Object> map = (Map<Object, Object>) raw;
+                Map<?, ?> map = (Map<?, ?>) raw;
 
-                for (Map.Entry<Object, Object> entry : map.entrySet()) {
+                for (Map.Entry<?, ?> entry : map.entrySet()) {
                     Enchantment enchantment = Enchantment.getByName(entry.getKey().toString());
 
                     if ((enchantment != null) && (entry.getValue() instanceof Integer)) {