Safe85 is not safe for Mac file paths

[marchdown]

I see that you've recently got rid of % and substituted it with : to keep the total number of characters. I'd like to point out that this conflicts with what you say about file-path-safety in the table in the README.md

: was used as a path separator back in the Classic MacOS days, and the modern OS X still doesn't allow it or forces it into / in some edge cases.

[kstenerud]

Actually, : is allowed in filenames in HFS+ (all characters are, including NUL). It's just that the GUI layer will show it as /. In fact, if you create a file in Finder with / in it, the actual filename will contain : (because / would mess up the Unix utils). The only apps that choke on it are Microsoft apps (like Word) because they use the same codebase that manually checks for valid Windows filenames instead of asking the OS.