* all lookups to support config system
- added get_options to get full dict with all opts
- fixed tests to match new error messages
- kept inline string k=v parsing methods for backwards compat
- placeholder depredation for inline string k=v parsing
- updated tests and examples to also show new way
- refactored and added comments to most custom k=v parsing
- added missing docs for template_vars to template
- normalized error messages and exception types
- fixed constants default
- better details value errors
Co-authored-by: Felix Fontein <felix@fontein.de>
