Added avatar manager which will help when transfering and caching avatars. Using boost::filesystem. MD5 sum is used to identify avatars, different types of files are possible. Avatar cache (and the avatars provided) use for example <md5sum>.png as file names, so that no additional storage for the md5sum is required.

A cache directory with write permissions is required, however, as avatars are not cached in RAM.

src/core/crypthelper.h

@@ -32,7 +32,8 @@ struct MD5Buf
 	std::string ToString() const;
 	bool FromString(const std::string &text);
 
-	bool operator==(const MD5Buf &other);
+	bool operator==(const MD5Buf &other) const;
+	bool operator<(const MD5Buf &other) const;
 
 	unsigned char data[MD5_DATA_SIZE];
 };