Test release from unreleased upstream 3.1.1 with fixes for SeaMonkey 2.53.13

Test release from unreleased upstream 3.1.1 with fixes for SeaMonkey 2.53.13. Appears to work at least as well as 3.1.1 on 2.53.12: please test and report.

• Address compatibility issues with SeaMonkey 2.53.13

Thanks @UCyborg, frg <frgrahl@gmx.net>.

Full Changelog: 3.1.1...3.1.2

v3.1.1

Test release from unreleased upstream 3.1.1 with fixes for SeaMonkey 2.53.12

• Replace non-standard catch (ex if cond)
• Fixes from review against 3.0.9 (typos, prefer let ... of ...)

Full Changelog: 3.0.9.2...3.1.1

v3.0.9.2

Now also compatible with SeaMonkey 2.53.10

Full Changelog: 3.0.7...3.0.9.2