Pick up more packages

[dpwiz]

Added some of the stable/low-deps/core-ish packages.
Adopted apecs-* from Jonas.
Added ptrdiff to EKmett's list, needed to enable gl-block and geomancy.

[DanBurton]

lgtm. For clarity:

@ekmett - we took the liberty of listing ptrdiff under you.

@jonascarpay - apecs, apecs-gloss, and apecs-physics will be listed under @dpwiz now instead of you.

Ping me or another Stackage curator if there are any objections.

[DanBurton]

lucid-svg (not present) depended on by:
- [ ] geomancy-layout-0.1.1 (>=0). Alexander Bondarenko <aenor.realm@gmail.com> @dpwiz. Used by: test-suite


tasty-bench-0.5.1 ([changelog](http://hackage.haskell.org/package/tasty-bench-0.5.1/changelog)) (Andrew Lelechenko <andrew.lelechenko@gmail.com> @Bodigrim) is out of bounds for:
- [ ] apecs-stm-0.3 (>=0.3 && < 0.5). Alexander Bondarenko <aenor.realm@gmail.com> @dpwiz. Used by: benchmark

@dpwiz I skipped the geomancy-layout test suite (aa22d32) and the apecs-stm benchmarks (a5e560d) due to these constraints. You can ping me or open another PR if newer versions of these packages address those version bounds issues.