Handling of historical change logs and version number

[ludomal]

For discussion

Changelogs
In the code, there are some changelogs that are not up to date.
For example: https://github.com/openitu/STL/blob/dev/src/basop/README.md

Should we leave them as they are, remove them, or do we need to update these?

Version code
Almost all programs provide version information such as
https://github.com/openitu/STL/blob/dev/src/g711/g711demo.c#L182

Should we leave them as they are, remove them, or do we need to update these?

Originally posted by @dennisguse in #127 (comment)