Added unicode support

Replaced strings with rune-slices, which capture unicode codepoints more
accurately.

main.go

@@ -406,7 +406,7 @@ func main() {
 	startState := thompson(re_postfix)
 	// Read every string from stdin until we encounter an error. If the error isn't EOF, panic.'
 	for test_str, err = reader.ReadString('\n'); err == nil; test_str, err = reader.ReadString('\n') {
-		matchIndices := findAllMatches(startState, test_str)
+		matchIndices := findAllMatches(startState, []rune(test_str))
 		// Decompose the array of matchIndex structs into a flat unique array of ints - if matchIndex is {4,7}, flat array will contain 4,5,6
 		// This should make checking O(1) instead of O(n)
 		indicesToPrint := new_uniq_arr[int]()