Now that we have diverged from TLSharp[1], the new pre-release
versions pushed to nuget have different API and slightly
different behaviour so we want them to be marked as newer.
[1] since 4d09ac711d
Somehow for the previous commit hash, which had only numbers in its
short version (0122072), nuget failed with:
Run $date = get-date -format "yyyyMMdd-HHmm"
Attempting to build package from 'TgSharp.Core.csproj'.
Error NU5010: Version string specified for package reference '0.1.0-date.20200414-0908.git.0122072' is invalid.
File does not exist (TgSharp.0.1.0-date.20200414-0908.git.0122072.nupkg).
Now we remove the "." after "date" and "git" and use double-dash
to separate initial version from the sub-version.
