IMYplay 1.3 released

IMYplay 1.3 released.
Summary of changes:

• SDLv2 support,
• Improvements in the SDL backend,
• Fixed the MIDI backend on 64-bit systems,
• Fixed the EXEC backend with a missing parameter,
• Fixed uninitialized values in the JACK backend,
• Updates in the build system for DOS,
• Other compatibility improvements,
• Documentation updates and improvements,
• Translations rebuilt,
• New unit tests.