intelligently decide between "*_test.rb" and "test*.rb" files
proper abort
slight feature removal
support "-n PATTERN" option for test/unit
refactor Polyamory into modules; extract TestUnit logic
test coverage for TestUnit
minitest compatibility

testrb was in test/unit but not present in minitest.
Switch to `polyamory -t` runner.
add support for environment variables
refactor complex methods into smaller ones
more options for testing frameworks
RSpec support
add Cucumber support
add ability to execute multiple jobs
don't display empty ENV values in output
Merge branch 'rewrite'