Fixes an issue with missing ruby-devel on EL5 (VirtualBox)
Merge pull request #801 from senior/maint/1.5.x/ruby-devel-in-el-5

Fixes an issue with missing ruby-devel on EL5 (VirtualBox)
Merge branch '1.5.x' into 1.6.x

* 1.5.x:
  Fixes an issue with missing ruby-devel on EL5 (VirtualBox)