Definitions are now inherited.

Parent class definitions will be inherited by child classes.
Custom definitions are now merged with existing definitions.
Removed PHP 5.4 array literal
Merge pull request #3 from ascii-soup/Remove54ArraySyntax

Removed PHP 5.4 array literal
Merge branch 'DefinitionInheritance' of git://github.com/ascii-soup/Auryn into ascii-soup-DefinitionInheritance
Updated CHANGELOG
Added ProviderBuilder
Multiple updates, read on for more:

- All exceptions now inherit from Auryn\Exception
- Delegates are now lazily provisioned using Injector::execute (Issue #5)
- Moved test classes into a separate /test/fixture directory
Merge pull request #6 from ascii-soup/Auryn-4/ConfigurationFiles

Provider Builder for file-based configuration [incomplete]
Added ProviderBuilder::fromFile and lazy Provider instantiation in builder