Adjustments for Arch Linux

Hi!

Nice to see some activity in your repo! This motivated me to redo my old adjustments to autosshfs for Arch Linux (not messing up the commit messages this time), add one more (all binaries were recently moved to /usr/bin/ in Arch) and create a proper pull request, which you are seeing now. 

This version of the code works nicely on my side, but I am not sure if any of the changes will mess up autosshfs on other systems. If so, let me know and I will do my best to help resolving that. It would be nice to have Arch support merged into the main (your) repository.

By the way, there is an Arch package (well, PKGBUILD) for autosshfs now, which fetches the source from my forked repo at the moment:
https://aur.archlinux.org/packages/autosshfs-git/
Also, if you are interested, there is a forum thread:
https://bbs.archlinux.org/viewtopic.php?id=163303

Happy coding!

Carlos