InsertCommand now replaces if a region is selected + regression test.
Improve linear access to View.ScopeName by -75.25%.
Random access regresses with this change, but I think random access
isn't as important.

Name                        Old             New           Delta
BenchmarkScopeNameLinear    1597819 ns/op   395491 ns/op   -75.25%
BenchmarkScopeNameRandom       31.4 ns/op      143 ns/op  +355.41%