fix soversion at 7 Unfortunatley upstream apparently can't learn, and increments soversion with every new release, even if there's no reason to and the new library is completely backwards-compatible.
Undo this nonsense and keep soversion at 7 for now.
1.20.0 upped soversion again without any ABI changes.
spelling fixes: eventhough, shoudl, asyncronous, maxium, implicity These changes are carried in debian for a long time, some since 2016. The last one (implicity) is new in 1.20.0.
