Test fixes

I created a branch to work on updating RubyProf::Test. I added a test/test_test.rb file for testing that class (horrible name, but it follows convention... somewhat...).

I've also started writing a TESTING.rdoc file so there is instructions on how to setup the project for testing, since I had to figure some stuff out, as I could not find documentation on the requirements to run "rake test".

There is currently still lots of work to do, but I wanted to get this visible to the main repo.

I will keep this open until we get RubyProf::Test updated so it works with Ruby 1.9 and MiniTest, which is my goal.

- Adam