Add support for better block syntax

It would be nice to write tests more like in [Jasmine](http://pivotal.github.com/jasmine/). This means there should be some form of support for test blocks (subject + indented tests inside). This would mean that an individual test file should be able to contain multiple test cases and be able to form a suite/scenario itself.

Start by reading the repository's current test syntax and runner behavior, since the issue names no files or tests. Compare the existing format with Jasmine-style subjects and indented tests, then define how multiple cases and suite or scenario boundaries should work. Add coverage for the proposed syntax and verify the full test suite.

Written by the indexing model from the issue text.