Add support for Ubuntu WSL or prevent users from using

Installing forge using the `http://forge.jboss.org/sh | sh` command brought me a few issues.

First, the `type -p` is not support, neither `unzip` is installed by default.

After fixing this two problems ( Pretty much removing the -p options and installing unzip ), it broke my PATH, bringing tons of stuff from the windows PATH itself, making my bash unusable.

If needed, please, advert users to DO NOT use this script on WSL, or else, they need to fix both `.bashrc` and `.profile` before be able to launch WSL again.

Thanks in advance