src: Code style corrections in Block and Buffer

Change-Id: Ic63ef97fa1e9f0d993ac2d9eb177628aa55c773a
name: Implementing appendNumber/toNumber to use nonNegativeInteger

appendVersion/appendSegment and toVersion/toSegment are now aliases for
appendNumber/toNumber.

Change-Id: I6cd549978601051bd6e288f2e7ebb95e3d97187b
Refs: #1361