0.8.0

Added

• Allow swapping built-in renderers without using their fully qualified names (#84)
• Lots of unit tests (for existing code)
• Ability to include arbitrary functional tests in addition to spec-based tests

Changed

• Dropped support for PHP 5.3 (#64 and #76)
• Bumped spec target version to 0.19
• Made the AbstractInlineContainer be abstract
• Moved environment config. logic into separate class

Fixed

• Fixed underscore emphasis to conform to spec changes (commonmark/commonmark-spec#317)

Removed

• Removed PHP 5.3 workaround (see commit 5747822)
• Removed unused AbstractWebResource::setUrl() method
• Removed unnecessary check for hrule when parsing lists (#85)