The new autoflash scripts allow flashing just by double-clicking a hex file (assuming of course your usbasp is hooked up). You first need to associate the appropriate bat file included. To do that, right click on the one for your chip and run as administrator. It will associate itself as the default program for opening hex files. Then just double click a hex and it flashes.
You may want to edit the bat file for fuses you like, but the included ones should work with HD. Although actually I should double check the attiny13 fuses.
The Makefile also works in linux now, so there's auto-building and auto-flashing all around. For the linux Makefile, I just downloaded the toolchain from here:
https://www.arduino.cc/en/Main/Donate
And unzipped it into / without installing it.
There seems to be another toolchain package availabel from Atmel (probably the more normal one), and if you use that or even just a different version number, you'll need to edit the Makefile paths to point to it. I will probably update the Makefile to point to a more normal Atmel installation soon. That's just the first link I found for whatever reason. I don't usually compile in linux, but it did work.