Move some unicode handling stuff to a separate file.

c/jv_unicode.h

@@ -0,0 +1,7 @@
+#ifndef JV_UNICODE_H
+#define JV_UNICODE_H
+int jvp_utf8_decode_length(char startchar);
+
+int jvp_utf8_encode_length(int codepoint);
+int jvp_utf8_encode(int codepoint, char* out);
+#endif