Add multiplatform support for install script.
Add multiplatform support for install script.

denmojo/pygrow,grow/pygrow,codedcolors/pygrow,denmojo/pygrow,vitorio/pygrow,grow/pygrow,denmojo/pygrow,codedcolors/pygrow,grow/grow,denmojo/pygrow,grow/grow,grow/grow,vitorio/pygrow,grow/grow,vitorio/pygrow,codedcolors/pygrow,grow/pygrow