Remove ucore_ prefix from headers and source files

src/gcd64.c

@@ -0,0 +1,13 @@
+#include "ucore/math.h"
+
+uint64_t 
+uc_gcd_64(uint64_t a, uint64_t b)
+{
+	while (b != 0) {
+		uint64_t t = b;
+		b = a%b;
+		a = t;
+	}
+
+	return a;
+}