fix for truncating newest messages from cache
fix docstring typo (thanks @jerith)
off by one errors because we are counting things in Redis differently now (thanks @jerith)
Revert "off by one errors because we are counting things in Redis differently now (thanks @jerith)"

This reverts commit 0cddb54744ca87eadd0606af5230d48292291a63.
ensure we leave exact number of entries we asked (thanks @jerith)
Merge branch 'feature/issue-766-fix-message-truncation' into develop