+extern std::string make_digest (boost::filesystem::path filename, boost::function<void (float)>);
+extern std::string make_digest (Data data);
+extern bool empty_or_white_space (std::string s);
+extern bool ids_equal (std::string a, std::string b);
+extern std::string remove_urn_uuid (std::string raw);
+extern void init ();
+
+extern int base64_decode (std::string const & in, unsigned char* out, int out_length);
+extern boost::optional<boost::filesystem::path> relative_to_root (boost::filesystem::path root, boost::filesystem::path file);
+extern FILE * fopen_boost (boost::filesystem::path, std::string);
+extern std::string file_to_string (boost::filesystem::path, uintmax_t max_length = 65536);
+extern std::string private_key_fingerprint (std::string key);
+extern xmlpp::Node* find_child (xmlpp::Node const * node, std::string name);
+extern std::string openjpeg_version();
+extern std::string spaces (int n);
+extern void indent (xmlpp::Element* element, int initial);
+extern std::string unique_string (std::list<std::string> existing, std::string base);