Windows user -> please test https://github.com/wraitii/0ad/tree/sm60
Mostly minor stuff:
- JSVOID->JSUNDEFINED
- compartment behaviours change
- Bug 1308236 - avoid ambiguous comparison
- Bug 1421358, REFRESH_FRAME was removed. TBH not sure this is useful, so go APIé
- ClassOps changes
- Proxy improvements post SM60