Fix RBAC permission matching negative rules

Merge pull request #258 from CakeDC/issue/rbac-negative-rules-30

fix bug on rule calculation when negative rules matched

Added prefixes to RBAC permission matchers

3.1.1

Update composer.json

Added prefixes to RBAC permission matchers

3.0.1

Update composer.json

Fixed unit tests for CakePHP 2.7

2.1.3

Update CHANGELOG.md