I've uploaded B2. The B1 version hardcoded the library name to "tidylib.so".
B2 introduces a load() function which specifies the path to the library:

require 'tidy'
Tidy.load('path/to/tidylib.so')

This avoids the hard coding of the name. Ideally I'll then be adding some
auto-detection which will search the RUBYLIB/RUBYPATH/PATH directories for
files named (tidy|tidylib|libtidy).(dll|so) etc. so that in the end no one
will ever have call this function in their scripts.