The following functionalities are added to configure aerc ui styles.
- Read stylesets from file with very basic fnmatch wildcard matching
- Add default styleset
- Support different stylesets as part of UiConfig allowing contextual
styles.
- Move widgets/ui elements to use the stylesets.
- Add configuration manual for the styleset
This command uses the Postpone folder from the account config to save
messages to. Messages are saved as though they were sent so have a valid
'to' recipient address and should be able to be read back in for later
editing.
