Create quads hierarchy

* Move nquads into quad.
* Create cquads simplified parser in quad.
* Move Triple (renamed Quad) to quad.

Also made sure mongo actually implements BulkLoader.

quad/cquads/parse.rl

@@ -0,0 +1,58 @@
+// GO SOURCE FILE MACHINE GENERATED BY RAGEL; DO NOT EDIT
+
+// Copyright 2014 The Cayley Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cquads
+
+import (
+	"fmt"
+	"unicode"
+
+	"github.com/google/cayley/quad"
+)
+
+%%{
+	machine quads;
+
+	include "actions.rl";
+
+	include "cquads.rl";
+
+	write data;
+}%%
+
+func parse(data []rune) (quad.Quad, error) {
+	var (
+		cs, p int
+		pe    = len(data)
+		eof   = pe
+
+		subject   = -1
+		predicate = -1
+		object    = -1
+		label     = -1
+
+		isEscaped bool
+		isQuoted  bool
+
+		q quad.Quad
+	)
+
+	%%write init;
+
+	%%write exec;
+
+	return quad.Quad{}, quad.ErrInvalid
+}