Split up is*rune() and to*rune() functions into individual source files

This optimizes the binary size for each tool that uses these functions.
Previously, if a program just used one single function, maybe even a
one-liner, it would statically compile in all lookup-tables, bloating
the binary by up to 20K.
All these changes are derived from a local libutf where I do the
primary changes. So I hope that I can merge these things into libutf
sooner or later, as discussed on the ml.

libutf/istitlerune.c

@@ -0,0 +1,32 @@
+/* Automatically generated by mkrunetype.awk */
+#include <stdlib.h>
+
+#include "../utf.h"
+#include "runetype.h"
+
+static Rune title2[][2] = {
+	{ 0x1F88, 0x1F8F },
+	{ 0x1F98, 0x1F9F },
+	{ 0x1FA8, 0x1FAF },
+};
+
+static Rune title1[] = {
+	0x01C5,
+	0x01C8,
+	0x01CB,
+	0x01F2,
+	0x1FBC,
+	0x1FCC,
+	0x1FFC,
+};
+
+int
+istitlerune(Rune r)
+{
+	if(bsearch(&r, title2, nelem(title2), sizeof *title2, &rune2cmp))
+		return 1;
+	if(bsearch(&r, title1, nelem(title1), sizeof *title1, &rune1cmp))
+		return 1;
+	return 0;
+}
+