Version pre-alpha-0.13 has been created.
Generelly I recommend always using the newest version, until a stable version has been created.
This version pre-alpha-0.13 (0.00.13 for ruby-gems) has the major source file longdecimal.rb renamed to long-decimal.rb, which is what is expected by rubygems. You can now download the gem and install it with
gem install long-decimal
and us it with
require "rubygems"
require_gem "long-decimal"
It is still not possible to use gem for downloading the gem, so you have to download it first manually and then step into the directory where the downloaded gem is, in order to install it with gem install.

Otherwise this version is identical with previous pre-alpha-0.12 and complete in terms of functionality. Future work will go into more tests, potential bug-fixing and better documentation. I expect to create a alpha version within the next few weeks.

Please observe that this is still pre-alpha-version.