Crash reports

source: docs/crash-reports.md @ a633e56

Every crash so far has been a single wrong type or a lost value somewhere in the reconstruction, and each one fixed takes a class of others with it. So a report helps.

• The mingw build writes a report with a symbolised stack trace to d2crash-<date>-<time>.txt next to the executable.
• The Visual C++ build writes Crash.txt and a minidump to BlizzardError/<date time>/ in the game folder.

Attach the file to an issue, with what you were doing when it happened.