Made a test in the MergingMapperTest which handles a smaller base test
which fits into the text-to-merge. This test also includes the merging
of a token which is merged from the text-to-merge into the base text.

Reimplemented "normalizeTextualLayer" and refurbished alignText.
Implemented mergeTokens which merges the tokens, moves the token
annotations and meta annotations and also moves the annotations and meta
annotations of the text-to-merge to the base text.