Various additions and bugfixes from GLASS methods

I copied the miscellaneous patches and additions we are using in Yesplan:
- ZipArchive extensions (reading from filename and replace an archive member)
- CharacterCollection>>format: to support a Dictionary argument
- Behaviour extensions (allMethods and allSelectorsBelow)
- Timespan fixes to support both Date and DateAndTime instances (like in Pharo)

Some of these methods override GLASS methods. We should coordinate if they should move or not. In the meantime, I wanted to share these extensions we have been using already in Yesplan for a long time.