Fixed several bugs from the new file i/o setup.

In particular:
1. Windows CR/LF weren't read properly (issue #11)
2. Scanning wasn't reading EOF properly
3. Documents may be empty (this was old, I think)
Also fixed some VS2008 warnings on /W4.

src/stream.h

@@ -5,6 +5,19 @@
 
 namespace YAML
 {
+	// a simple buffer wrapper that knows how big it is
+	struct Buffer {
+		Buffer(char *b, int s): buffer(b), size(s) {}
+
+		operator bool() const { return size > 0; }
+		bool operator !() const { return !static_cast <bool> (*this); }
+		char operator [] (int i) const { return buffer[i]; }
+		const Buffer operator + (int offset) const { return Buffer(buffer + offset, size - offset); }
+
+		char *buffer;
+		int size;
+	};
+
 	class Stream
 	{
 	public:
@@ -14,7 +27,7 @@ namespace YAML
 		operator bool() const;
 		bool operator !() const { return !static_cast <bool>(*this); }
 
-		const char *current() const { return buffer + pos; }
+		const Buffer current() const { return Buffer(buffer + pos, size - pos); }
 		char peek();
 		char get();
 		std::string get(int n);