Mouse buttons all act the same

[KaiJan57]

With a recent commit, all mouse buttons send the same escape code to e.g. vim, breaking much of mouse=a functionality, i.e. text selection, scrolling etc, as all the events are interpreted as clicking.
This can easily be fixed by removing int code and replacing all references to it by button, though the proper way is to sync with upstream

[sbradnick]

I noticed I was suffering from this too. After 4c57f1f things are certainly better; for instance, switching tabs works again (vs. opening new ones over and over per click). I can scroll up with the mouse wheel - if I use page-down a few times first - but I can't scroll down.