Is it even possible to run OneWire library on this processor.
Sketch for the 328 processor is about 6kB.
The code will fit. That's one obstacle out of the way. At this point, do what I would do, run and see what happens.
What was weird that the sketch for attiny is smaller (about 3kB). But than i figured out that it will be some parts needed for 328 and not needed for attiny.
Unfortunately, that much of a difference is very suspicious. It's possible that the OneWire library does not have conditional compilation entries for the ATtiny85. Where did you get the library?
I didn't tried tuned the oscilator because i don't know how to do that
Give this a try...http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1287558192
I have favour. I don't quiet understand how i will change the fuses. From what i found out. It's needed to pick a board with a ATtiny85 and than i will upload the bootloader for arduino? But i don't know which one.
For "burn bootloader" to change the fuse settings, you have to use the core I referenced. Have you downloaded and installed that core? Does that core appear to be working for you? Are you able to build Sketches?