Fix split() for strings ending with the split

Allow `split()` (and non-regex `reg_split()`) to match the split on the last possible part of the string as well.
Fixes `split('b', 'ab')` resulting in `{'ab'}`, rather than `{'a', ''}`.

Author: Pieter12345

src/main/java/com/laytonsmith/core/functions/StringHandling.java

@@ -1328,7 +1328,7 @@ public Mixed exec(Target t, Environment env, Mixed... args) throws CancelCommand
 				return array;
 			}
 			int splitsFound = 0;
-			for(int i = 0; i < string.length() - split.length() && splitsFound < limit; i++) {
+			for(int i = 0; i <= string.length() - split.length() && splitsFound < limit; i++) {
 				if(string.substring(i, i + split.length()).equals(split)) {
 					//Split point found
 					splitsFound++;