v0.6.1

Starting with this release, we now publish macOS binaries!

Added:

• RGBASM prints a specific error message for leftover diff marks (+ and -)
• RGBLINK has improved .map file output:
  • EMPTY blocks have address ranges, and fixed indentation and duplicates
  • ; Next union/fragment comments have fixed indentation and placement
• RGBGFX supports - for stdin and stdout

Fixed:

• RGBGFX terminates if opening a file fails
• Fix some possible build errors on some systems
• RGBLINK could crash when merging SECTION FRAGMENTs that aren't in ROM
• RGBLINK mangles absolute SECTION names to support SDCC "areas"
• RGBGFX could crash on empty palette slots with "Assertion 'this->_M_is_engaged()' failed."; we hardened our test configuration to catch more bugs like this

A big thank you to @eievui5 and @pinobatch for additional testing during the development of this version, as well as @rlewicki for some improvements to the codebase!