Fix package name in symbols file
Make libpromses a private library
Imported Upstream version 3.6.1
Merge tag 'upstream/3.6.1'

Upstream version 3.6.1
Update changelog
Override Lintian messages about symbols file
Fix NMU version
Imported Upstream version 3.6.2
Merge tag 'upstream/3.6.2'

Upstream version 3.6.2
Update changelog