Document how debug mode works

[tehKaiN]

• [x] how to enable debugging during ACE build
• [x] add debug build instructions in tutorial
• [x] logging only available there
• [x] mem vs game log
• [x] additional safety checks

[tehKaiN]

First two are done in ce4efa4e82ec01edcffce98814bee998f51597d6 and 4f8e078affcc9f9a1c5da75a179a2d321ce62131 !

[tehKaiN]

last three done in beb665b618bfcebae9aacd0016b5723a79b55bc7 !