WIP: Moved sources int src/, separated most of the source code from Perl.

The XS was left only for the unit / integration tests, and it links
libslic3r only. No wxWidgets are allowed to be used from Perl starting
from now.

src/slic3r/Utils/Time.hpp

@@ -0,0 +1,25 @@
+#ifndef slic3r_Utils_Time_hpp_
+#define slic3r_Utils_Time_hpp_
+
+#include <string>
+#include <time.h>
+
+namespace Slic3r {
+namespace Utils {
+
+// Utilities to convert an UTC time_t to/from an ISO8601 time format,
+// useful for putting timestamps into file and directory names.
+// Returns (time_t)-1 on error.
+extern time_t parse_time_ISO8601Z(const std::string &s);
+extern std::string format_time_ISO8601Z(time_t time);
+
+// Format the date and time from an UTC time according to the active locales and a local time zone.
+extern std::string format_local_date_time(time_t time);
+
+// There is no gmtime() on windows.
+extern time_t get_current_time_utc();
+
+}; // namespace Utils
+}; // namespace Slic3r
+
+#endif /* slic3r_Utils_Time_hpp_ */