add benchmark + some todos
microoptimization for appending

from
New large keyset:               145587
to
New large keyset:               137849
ksLookup: use stack instead of allocation

from
Lookup key database:                36414 Microseconds
to
Lookup key database:                35870 Microseconds
avoid allocation of key in ksLookupByName

a relevant optimization..
(the previous one was marginal)

from
Lookup key database:                36342 Microseconds
to
Lookup key database:                27980 Microseconds