A first step towards refactoring the module.
Unfortunately the config is not consistent in using comma-separated
values or repeated keys for lists, since the user can always add commas
by themselves, we should default to repeated keys in the generator.
* ssh: add generic Match support for matchBlocks
Introduce conservative support for actual `Match`
blocks in ssh config.
"Conservative" means this PR doesn'tt try to process
the `match` expression and simply uses it as a string
provided by the user.
If set, `match` has precedence over `host` meaning
if both are set, `match` is used and `host` is ignored.
* Add news entry
