Fixes #176. Update to 1.8.1 and add cross-platform instructions.
Fixes #176. Update to 1.8.1 and add cross-platform instructions.

fenhl/hematite,LeeRisk/hematite,toqueteos/hematite,fenhl/hematite,bvssvni/hematite,bvssvni/hematite,0x73/hematite,toqueteos/hematite,PistonDevelopers/hematite,LeeRisk/hematite,0x73/hematite,PistonDevelopers/hematite