Release 1.0
Update docs
Update installation link
Fix image sizing
Fix tar command to work with both GNU and BSD tar

Prevent install failure if the user's `tar` command is GNU tar (e.g. because they installed that via Fink / MacPorts / Homebrew). The revised instructions work with Apple's BSD tar just as well as with GNU tar.
Merge pull request #123 from fingolfin/patch-1

Fix tar command to work with both GNU and BSD tar
Present alert for users on OS X 10.8
Merge pull request #125 from supermarin/marvericks-warning

Present alert for users on OS X 10.8
fix updates