Merge latest dive changes for slice, array and maps

[deankarn]

benchmarks have slightly increased b/ops for this functionality

$ go test -cpu=4 -bench=. -benchmem=true
PASS
BenchmarkValidateField-4             3000000           439 ns/op         192 B/op          2 allocs/op
BenchmarkValidateStructSimple-4      1000000          2382 ns/op         656 B/op         10 allocs/op
BenchmarkTemplateParallelSimple-4    2000000           910 ns/op         656 B/op         10 allocs/op
BenchmarkValidateStructLarge-4        100000         13201 ns/op        4309 B/op         60 allocs/op
BenchmarkTemplateParallelLarge-4      300000          5240 ns/op        4311 B/op         60 allocs/op

for #78