Implement a lot of position moving functions

src/basic/string16.cpp

@@ -18,6 +18,16 @@ bool IsSymbol(wchar_t w) {
     return result;
 }
 
+bool IsNonWord(wchar_t w) {
+    bool result = IsSymbol(w) || IsWhitespace(w);
+    return result;
+}
+
+bool IsWord(wchar_t w) {
+    bool result = IsSymbol(w) || IsWhitespace(w);
+    return !result;
+}
+
 bool IsAlphabetic(wchar_t a) {
     bool result = (a >= 'a' && a <= 'z') || (a >= 'A' && a <= 'Z');
     return result;