scroll/TODO

 * strlen function which is aware of unicode
 * Alternative Screen mode detection
 * scroll down function
 * scroll/jump to buttom on new input
 * make scroll configurable by config.h in suckless style
   - configure option for scrollup/-down hotkeys
   - configure option for scroll lenght: nth-linewise and/or pagewise
   - configure option for scrollbackbuffer size
 * manpage
 * install target in Makefile