Fixes after my initial run

I encountered a number of issues when I initially pulled down and ran the 8installer.sh script tonight, which included:

* Starting within the pimame_installer directory, and thus relative paths screwed everything up.
* Genesis roms paths was missing the pimame directory
* Scraper didn't work

I'm unsure about the pip-install python-levenshtein as I note you have this in the build/ of pimame-menu, but adding this step enabled scraper to work for me.