Prior to this commit, the composer was based on a map[string]string.
While this approach was very versatile, it lead to a constant encoding / decoding
of addresses and other headers.
This commit switches to a different model, where the composer is based on a header.
Commands which want to interact with it can simply set some defaults they would
like to have. Users can overwrite them however they like.
In order to get access to the functions generating / getting the msgid go-message
was upgraded.
Aerc usually used the path []int{1} if it didn't know what the proper path is.
However this only works for multipart messages and breaks if it isn't one.
This patch removes all the hard coding and extracts the necessary helpers to lib.
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
