Minor: use right .end() to check error.
Added test that compares output to the paper's.

- That is, I added a pipeline to run REF-EVAL on the data used in the
  DETONATE paper and compare the scores to those we used for the
  DETONATE paper. This functions as a regression test.
Added further examples to documentation.
Minor: Improved status messages.
Included CMake, which is needed to build Lemon.