Switch the active_model plugin spec to work on Windows and Java
Switch the active_model plugin spec to work on Windows and Java

Previously, the active_model plugin spec forked in order to run
the active model lint tests, which use test/unit instead of
rspec.  Now it uses the test/unit API to run them.

Unfortunately, because test/unit was replaced by minitest in
ruby 1.9, and the old test/unit API isn't supported, we have
to roll our own test suite runner on ruby 1.9.

offshore-safety/sequel,beni55/sequel,pfarrell/sequel,t-morgan/sequel,uhoh-itsmaciek/sequel,knut2/sequel,tmm1/sequel,dennis-d/custom_sequel,gferguson-gd/sequel,reubano/sequel,bigfix/sequel,mpalmer/sequel,yazshel/sequel,chef/sequel,freshpay/sequel,dennis-d/custom_sequel,nicohvi/sequel,seeARMS/sequel,Marketcircle/sequel,offshore-safety/sequel,davidbegin/sequel,yazshel/sequel,nju520/sequel,nju520/sequel,offshore-safety/sequel,mpalmer/sequel,davidbegin/sequel,freshpay/sequel,uhoh-itsmaciek/sequel,seeARMS/sequel,t-morgan/sequel,pfarrell/sequel,knut2/sequel,beni55/sequel,gferguson-gd/sequel,reubano/sequel,nicohvi/sequel