Fix for non-glibc linux environments
Merge pull request #367 from Ptico/master

Fix for non-glibc linux environments
Add ruby 2.1 to the list of cross build ruby versions for Windows.
Merge pull request #369 from larskanis/add_cross_ruby_2.1

Add ruby 2.1 to the list of cross build ruby versions for Windows.
bump to 1.9.4