Use compilation-scroll-output, remove rspec-end-of-buffer-target-window

The effect seems to be the same
Define rspec-compilation-mode, use it in rspec-compile

* Set only buffer-local values, should fix #41
* Get rid of (expand-file-name), it didn't work and broke the highlighter
* Include the whole (relative) file path in the first group
* Highlight "xx examples, xx failures, xx pending" in red or green
* Highlight Pending: and Failures: without relying in the default highlighting
Merge pull request #42 from dgutov/compilation

Improve compilation behavior