Port FlatBuffers to Go.

Implement code generation and runtime library for Go, derived from the
Java implementation. Additionally, the test suite verifies:

 - the exact bytes in the Builder buffer during object construction,
 - vtable deduplication, and
 - table construction, via a fuzzer derived from the C++ implementation.

Change-Id: Ib95a019c684891def2b50281e570b4843fea7baa

tests/MyGame/Example/Any.go

@@ -0,0 +1,8 @@
+// automatically generated, do not modify
+
+package Example
+
+const (
+	AnyNONE = 0
+	AnyMonster = 1
+)