incr.comp.: Make path's of session directories slightly shorter.
incr.comp.: Make path's of session directories slightly shorter.

By using "s-" instead of "sess-" as a prefix and encoding numbers as base36 instead of base16.

GBGamer/rust,graydon/rust,graydon/rust,aidancully/rust,aidancully/rust,graydon/rust,GBGamer/rust,GBGamer/rust,GBGamer/rust,aidancully/rust,aidancully/rust,GBGamer/rust,graydon/rust,GBGamer/rust,graydon/rust,aidancully/rust,GBGamer/rust,aidancully/rust,GBGamer/rust,graydon/rust