Related to #500.

When .replace rule is used and -X switch is passed in runtime,
replaced characters should be shown in trace output.

There are small differences between diphone set of the voices, but they are not used from espeak-ng

considering it may not be immediately after consonant

This group is used as a padding between consonant letter and its other diacritics
which may be in arbitrary order

I am not sure if I translated this right. Do the flat and sharp emojis really refer to music?

as all other letters are already there from Cyrillic.

1. only in separate words,
2. at the end of entered text.

Letter groups A, B, C, E etc. should be redefined in C code
t https://github.com/espeak-ng/espeak-ng/blob/master/docs/dictionary.md#redefinition-of-charater-groups

As Shadda is diacritic mark, it doesn't have meaning as separate letter,
therefore it should be consumed together with diacritized letter.