Implicit bugfix thanks to refactoring

The _extra_scroll_events counter is reset now when it's necessary.


git-svn-id: svn+ssh://svn.code.sf.net/p/mcomix/code@954 ef8490bc-f317-4725-81ed-e95a9aca1bcf
Renaming a parameter


git-svn-id: svn+ssh://svn.code.sf.net/p/mcomix/code@955 ef8490bc-f317-4725-81ed-e95a9aca1bcf