Implemented test case that demonstrates how it could work, currently failing.
Reverted changes to createCondition(), not needed.
Implemented Rules State handling and moved rules expression interface to all use rules expressions.
Moved the empty summary default for test condition plugins out of the base class.
Fixed typos in comments.
Added 2 interfaces for action expression and condition expression plugins.
Fixed invocation of phpunit in Travis CI test suite.
Merge pull request #68 from klausi/travis-phpunit-fail

Fix invocation of phpunit in Travis CI test suite.
Merge pull request #67 from klausi/rules-expression-base

Interfaces for action expression and condition expression plugins.
Removing workarounds for PHPUnit Bug now that we are running on PHPUnit 4.
Refactoring context system overrides out of Rules.